Manufacturing method for wiring circuit substrate

ABSTRACT

A method is provided for manufacturing a multi-layer wiring circuit substrate. A first metal layer is selectively etched in first areas to reduce a thickness of the metal layer in the first areas and to form protrusions in other areas which extend above the etched areas. An interlayer-insulating layer is formed to overlie the etched areas of the first metal layer. The interlayer-insulating layer has an inner surface which confronts the etched first areas and an outer surface remote from the inner surface, such that the protrusions extend through the interlayer-insulating layer and have ends exposed at the outer surface. A second metal layer is then provided in conductive communication with the exposed ends of the protrusions, and the first and second metal layers are selectively patterned from surfaces remote from the interlayer-insulating layer.

This application is a division of Ser. No. 10/139,237 filed May 7, 2002,U.S. Pat. No. 6,828,221 issued Dec. 7, 2004, which in turn, is adivision of Ser. No. 09/685,799 filed Oct. 11, 2000 U.S. Pat. No.6,528,874 issued Mar. 4, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wiring circuit substrate used formounting electronic devices, such as integrated circuits (ICs) and largescale integrated circuits (LSI circuits). Particularly, the inventionrelates to a wiring circuit substrate that allows high-density mountingto be implemented.

Furthermore, the present invention relates to a manufacturing method forthe aforementioned wiring circuit substrate.

2. Description of the Related Art

FIGS. 54A to 54F and 55A to 55C are used to describe a conventionalexample of a high-density-mounting wiring circuit substrate. Thesefigures are cross-sectional views illustrating a manufacturing methodfor the conventional wiring circuit substrate in the order of steps (A)to (I) described below.

Step (A)

First of all, as shown in FIG. 54A, a base 1 is prepared. The base 1 ismade of an insulating sheet having a thickness of 25 to 100 μm. In thebase 1, interlayer-connecting openings 2 are formed by using a punchingmachine or a drill or by performing laser processing.

Step (B)

Subsequently, as shown in FIG. 54B, conductive paste 3 (made of a mainmaterial, for example, such as silver or copper) is filled into theopenings 2 by using a printing method for example. Thereby, theinsulating base 1 is arranged to be a semi-cured sheet A in which theconductive paste 3 is filled into the openings 2.

Step (C) and Step (D)

Subsequently, as shown in FIG. 54C, metal foils 4 made of, for example,copper, are individually arranged over two faces of the sheet A. Then,as shown in FIG. 54D, the metal foils 4 are overlaid by using apressing/heating press. Thereby, a multilayer body is formed such thatthe metal foils 4 are formed on the two faces, an insulating sheet isprovided therebetween, and the metal foils 4 on the two faces areelectrically connected to each other via the conductive paste 3 in theopenings 2.

Step (E)

Subsequently, resist films 5 are formed on the metal foils 4. The resistfilms 5 have the same pattern as that of conductor circuits that will beformed. FIG. 54E shows a state after the resist films 5 are formed.

Step (F)

Subsequently, using the aforementioned resist films 5 as masks, etchingis performed for the aforementioned metal foils 4, thereby formingconductor circuits 6, as shown in FIG. 54F. According to the above,layers are separated and arranged on the two faces via the insulatingsheet (base) 1, and a multilayer body B having the conductor circuits 6interlayer-connected to each other via the conductive paste 3 in theopening 2 is formed.

Step (G)

Subsequently, as shown in FIG. 55A, on individual two faces of theaforementioned multilayer body B, insulating sheets 1 a having openings2 filled with conductive paste 3 and metal foils 4 a are overlapped witheach other. Thereafter, these component members are stacked with eachother by using a press, and a multilayer body C is thereby formed.

Step (H)

Subsequently, as shown in FIG. 55B, resist films 5 are selectivelyformed on the metal foils 4 a on two faces of the multilayer body C.

Step (I)

Subsequently using the resist films 5 as masks, etching is selectivelyperformed for the metal foils 4 a, thereby performing patterningtherefor to form wiring films 6 a, as shown in FIG. 55C. Thereby, awiring circuit substrate 7 having four layers of the conductor circuits6 and 6 a are formed.

FIGS. 56A to 56G are used to explain another conventional example of ahigh-density-mounting wiring circuit substrate. These figures arecross-sectional views illustrating a manufacturing method for theconventional wiring circuit substrate in the order of steps (A) to (G)described below.

Step (A)

For example, as shown in FIG. 56A, a metal foil 10 (having a thicknessof, for example, 18 μm) made of a copper material is prepared. Then, onthe metal foil 10, conductive protrusions 11 are formed by a printingmethod via conductive paste (made of a main material such as a silver orcopper material) and a metal plate, and then, are heated and cured. Theprotrusions 11 are thus formed so as to have thicknesses, for example,ranging from 100 to 300 μm.

Step (B)

Subsequently, as shown in FIG. 56B, an insulating adhesive sheet 12 isadhered onto the face on which the protrusions 11 of the aforementionedmetal foil 10 are formed. For the adhesive sheet 12, an adhesive sheethaving a thickness smaller than the thicknesses of the protrusions 11 isused. Thereby, the top of each of the protrusions 11 protrudes from thesurface of the adhesive sheet 12. A multilayer body A is produced thathas a configuration in which the protrusions 11 are formed on the metalfoil 10 and the adhesive sheet 12 is adhered onto the surface of themetal foil 10 in a state of allowing the top of each the protrusions 11to protrude therefrom.

Step (C) and Step (D)

Subsequently, as shown FIG. 56C, a metal foil 13 similar to theaforementioned metal foil 10 is arranged over the surface of theadhesive sheet 12, then, as shown in FIG. 56D, the metal foil 13 isoverlaid on the adhesive sheet 12 and the protrusions 11 according to aheating-pressing method. Thereby, a multilayer body B is produced.

Step (E)

Subsequently, for example, resist films for which patterning isperformed are formed on the metal foils 10 and 13 individually formed ontwo faces of the multilayer body B. Then, etching is performed for themetal foils 10 and 13 by using the resist films as masks, therebyforming conductor circuits 14 and 15. FIG. 56E shows a configurationwhere the resist films used as masks are removed after the conductorcircuits 14 and 15 are formed.

Step (F)

Subsequently, two multilayer bodies a are prepared. Each of themultilayer body (a) is formed by the same method as that for themultilayer body (A) shown in FIG. 48B. As shown in FIG. 56F, the twomultilayer bodies (a) are individually arranged over two faces of theaforementioned multilayer body (B).

Step (G)

The aforementioned multilayer body (B) is sandwiched by the multilayerbodies (a), and the integrated body is pressed from the sides of twofaces thereof according to the aforementioned heating-pressing method.Thereby, a wiring circuit substrate 16 as shown in FIG. 56G is produced.

Subsequently, a still another conventional technique will be explained.FIGS. 57A to 57E and 58A to 58D show a production process of stillanother wiring circuit substrate.

Step (A)

As shown in FIG. 57A, a copper-plated laminated plate 400 a is preparedfor forming a hole 400 b for connection therein by drilling or laserprocessing. The numeral 400 c is an insulating sheet to serve as thebase member for the laminated plate 400 a, and 400 d, 400 d are copperfoils formed on both sides of the insulating sheet 400 c.

Step (B)

Subsequently, as shown in FIG. 57B, a copper plating layer 400 e isformed on the entire surface by an electroless plating process and asubsequent electrolytic plating process.

Step (C)

Subsequently, as shown in FIG. 57C, the hole 400 b is filled with aninsulating resin 400 f, such as an epoxy.

Step (D)

Subsequently, as shown in FIG. 57D, both sides of the laminated plate400 a is smoothed by mechanical polishing. Thereafter, another copperplating layer 400 g is formed by an electroless plating process and asubsequent electrolytic plating process. Accordingly, the insulatingresin 400 f filling up the hole 400 b is covered by the copper platinglayer 400 g.

Step (E)

Subsequently, as shown in FIG. 57E, a wiring film 400 h is formed bypatterning the copper plating layers 400 g, 400 d, 400 e on both sidesof the laminated plate 400 a. The etching operation is executed byapplying a resist film, exposing and developing the same so as to form amask pattern, and selective etching with the mask pattern used as themask. After the etching, the resist film is eliminated.

Step (F)

Subsequently, as shown in FIG. 58A, an insulating resin 400 i, 400 i iscoated on both sides of the laminated plate 400 a. Thereafter, a hole400 j to be a through hole is formed in the insulating resin 400 i by alaser beam. At the time, the residual resin adhered on the surface ofthe copper foil 400 d should be eliminated by using a washing liquid.

Step (G)

Subsequently, as shown in FIG. 58B, a copper plating layer 400 k isformed on both sides of the laminated plate 400 a by an electrolessplating process and an electrolytic plating process.

Step (H)

Subsequently, as shown in FIG. 58C, a circuit 400 l is formed bypatterning the copper plating layers 400 k on both sides of thelaminated plate 400 a. The etching operation is executed by selectiveetching with a mask formed by patterning a resist film by exposing anddeveloping used as the mask. Thereafter, the resist film used as themask is eliminated.

Step (I)

Subsequently, as shown in FIG. 58D, both sides of the laminated plate400 a are covered selectively by a solder resist 400 m. Accordingly awiring circuit substrate 400 n is completed.

However, the conventional example shown in FIGS. 54 and 55 arisesproblems as described the followings. First, the openings 2 in theinsulating sheet 1 are filled with the conductive paste 3 made of a mainmaterial such as expensive silver material and are used for interlayerconnection. This arises a problem of increasing costs. Particularly,since arrangement density of the openings 2 is required to be increasedaccording to an increasing demand for high-density mounting, theincrease in costs becomes noticeable so as not to be ignored.

Second, when the conductive paste 3 is filled into the openings 2, theconductive material is adhered to portions other than the openings 2,although the amount thereof is very small. This arises a problem ofreducing the insulation resistance, particularly in a high-humidityenvironment.

Third, when press-overlaying is performed after the openings 2 areformed in the insulating sheet 1, the insulating sheet 1 is forced tohorizontally extend. Thereby, positional deviation of the openings 2occurs. Even by performing correction thereof and making openings, thecorrection is not effective in the high-density pattern. The positionaldeviation of the openings 2 causes defective interlayer connection,thereby arising serious problems, which cannot be ignored. Particularly,the problem is critical for the high-density-mounting wiring circuitsubstrate.

Fourth, the reliability of the connection between the metal foils 4 madeof a copper material and the conductive paste 3 is insufficient. Theconductive paste 3 filled into the openings 2 removes a solventcomponent so as to be a semi-cured state. The semi-cured conductivepaste shrinks because of removal of the solvent component and the like,thereby reducing the volume of its own. In addition, in most cases,upper and lower faces of the conductive paste 3 become in a concavestate. As a result, defective connection is apt to be caused between themetal foils 4, thereby arising a problem of reducing the reliability andthe yield.

Subsequently, the conventional example shown in FIGS. 56A to 56G alsoarises problems as described the followings. First, using theprotrusions 11 formed of the conductive paste also arises the problem ofincreasing costs.

Second, since a screen-printing method is used to form the protrusions11 with the conductive paste, increase in the thickness thereof isrestricted. Therefore, in most cases, screen-printing operations must berepeatedly performed to form the protrusions 11.

When the number of the printing operations is increased, the positionaldeviation of the protrusions 11 is apt to occur, and deformation of theprotrusions 11 is thereby apt to occur. This develops a problem ofreducing the reliability of the connections between the protrusions 11and the metal foils 4. In addition, positioning operation for thescreen-printing is very difficult and requires high-level skills,thereby causing a problem of requiring relatively long processing time.

These problems become increasingly apparent in proportion to reductionin the diameter of each of the protrusions 11. For example, forprotrusions each having a diameter of 0.3 mm, two printing operationsmust be performed; and for protrusions each having a diameter of 0.2 mm,four printing operations must be performed. This is heavy work anddisturbs improvement in the productivity, remaining problems to besolved for the provision of high-density wiring circuit substrates.

Third, still another problem arises in that heights of the protrusions11 are likely varied. In specific, in the screen-printing method, sinceit is difficult to uniform thicknesses of films, heights of theprotrusions 11 formed thereby are also likely to be variable. Thevariation in the thickness likely causes the connection between themetal foil 13 and the protrusions 11 to be defective. This results inarising a problem of reducing the yield and the reliability.

Fourth, in the manufacturing stage, the metal foil 10 basing the wiringcircuit substrate is as thin as, for example, 18 μm. Therefore, in thescreen-printing sufficient care must be taken to prevent it from beingwrinkled, deformed, and bent on the metal foil 13 side. Even a veryminor operation problem could reduce the yield. This develops to theproblem of increasing costs, which should not be neglected. Conversely,increasing the thickness of the metal foil 10 so as to obtain a strongbase also causes a problem of disturbing the conductor circuits to befinely patterned.

One of problems common to the described conventional examples is thatthere are restrictions in making the high-density arrangement, that is,in the arrangement of fine interlayer connection. In the case of oneexample, the printing operation is difficult because of the reduction inthe diameters of the openings and difficulty in filling the conductivepaste into the openings. In the case of another conventional example,the difficulty in the printing operation increases in proportion to thereduction in the diameters in bump printing. Thus, according to theconventional technology, an opening having a diameter smaller than 200μm cannot be produced.

In addition, since the strength of the connection between the conductivepaste and the copper foil is low, an excessively large area is requiredfor the connection.

Next, the wiring circuit substrate shown in FIGS. 57A to 57E and 58A to58D also involves problems.

A first problem is a poor adhesion property between the surface of theinsulating resin 400 f for filling the hole 400 b and the copper platinglayer 400 g so as to easily generate adhesion failure.

Particularly at the time of mounting, in the case various members areconnected with the area, there is a risk of generating fall-off.

Moreover, in order to solve the problem, the wiring circuit substrateneeds to be designed so as not to superimpose the connecting points ofthe various members and the hole 400 b formation area. Therefore, itgives the limitation in designing so as to be a cause for prohibiting ahigh density of the wiring circuit substrate.

A second problem is deflection of the surface of the copper platinglayer 400 k in the area with the hole 400 j because the copper platinglayer 400 k is formed in the area with the hole 400 j.

Therefore, a wiring layer cannot be formed further on the copper platinglayer 400 k, and thus a multi-layer structure cannot be provided.

A third problem is the inability of ensuring a sufficient film thicknessin the area with the hole 400 j because the copper plating layer 400 kis formed in the area.

That is, the copper plating layer 400 k is formed by an electrolessplating process and a subsequent electrolytic plating process. The filmformation rate in the electroless plating process is low. Furthermore,the film thickness irregularity can easily be generated in theelectrolytic plating process in relation to the electrolyticdistribution. Therefore, even in a level difference part for forming thehole 400 j, a film is formed with a thin film thickness so that asufficient film thickness cannot be ensured. This point has prohibitedrealization of minuteness of the wiring circuit substrate.

SUMMARY OF THE INVENTION

The present invention is made to solve the above-described problems. Anobject of the invention is to provide a wiring circuit substrate thatcan be manufactured without problems such as bending, breaking, anddeformation being caused and with dimensional stability being improved,thereby allowing improvement in the reliability of the connectionbetween upper and lower conductor circuits, and in addition, allowingreduction in the cost for an upper-lower-conductor-circuit connectingdevice. Another object of the present invention is to provide amanufacturing method for the wiring circuit substrate.

Moreover, another object of the present invention is to provide a wiringcircuit substrate without deflection of a wiring film on both sides of asubstrate in a formation area of a hole (through hole) so as to enablefurther lamination of another wiring film, or the like on the wiringfilm, capable of forming a wiring film in a minute pattern with anecessary thickness, and a production method for the wiring circuitsubstrate.

To these ends, according to one aspect of the present invention, thereis provided a wiring circuit substrate comprises a metal layer forforming conductor circuits, an interlayer-insulating layer formed on themetal layer, and protrusions for interconductor connection that areselectively formed on the metal layer in a state of passing through theinterlayer-insulating layer and that are formed of the same metal asthat for the metal layer.

In the present invention, the metal layer for forming the conductorcircuits and the protrusions are formed of the same material. Therefore,a simply structured member can be used as a base member that allows themetal layer and the protrusions to be formed, thereby allowing costs forthe material to be reduced. The protrusions can be formed by performinghalf-etching for the base member. Also, the above does not require astep of removing an interlayer-insulating layer (which will be describedbelow), thereby allowing manufacturing time to be reduced, and alsoallowing reduction in the price of the wiring circuit substrate to beimplemented.

According to another aspect of the present invention, a wiring circuitsubstrate comprises a first metal layer for forming first conductorcircuits, an interlayer-insulating layer formed on the first metallayer, protrusions for interlayer connection that are selectively formedon the metal layer in a state of passing through theinterlayer-insulating layer and that are formed of the same metal asthat for the first metal layer, and a second metal layer that is formedon the protrusions and the interlayer-insulating layer and that is usedfor forming second conductor circuits.

According to the invention, a simply structured member can be used as abase member that allows forming of the metal layer and the protrusionsthat are selectively formed. This allows material costs to be reduced,and also, allows manufacturing time to be reduced. Accordingly,reduction in the price of the wiring circuit substrate can beimplemented.

According to still another aspect of the present invention, a wiringcircuit substrate comprises an insulating layer having at least one faceon which first conductors of either a single layer or multiple layersare formed and openings for securing paths for electrical connection tothe first conductor circuits are formed. It also comprises aninterlayer-insulating layer formed on the one face of the insulatinglayer in which the openings are formed, protrusions formed of aconductor-forming metal layer in a state of passing through theinterlayer-insulating layer at positions opposing the openings, andsecond conductor circuits formed on surfaces of the protrusions and theinterlayer-insulating layer. In addition, the protrusions areelectrically connected to the first conductor circuits through theopenings, and also, electrically connects the first conductor circuitsand the second conductor circuits to each other.

According to the above, the protrusions electrically connected to thefirst conductor circuits via the openings are provided. In short,electrical connection can be performed through the openings. This allowsthe wiring circuit substrate to be press-overlaid from any one of theface on which the protrusions are formed and the face on which the firstconductor circuits are formed. In this case, the second conductorcircuits may be a wiring circuit substrate. Thereby, a very large numberof layers of conductor circuits of the wiring circuit substrate can beformed, thereby allowing the mounting density to be increased.

In the above, it is preferable that a conductive adhesion film be formedon the top of each of the protrusions. This improves the reliability ofconnections between the protrusions and the conductor circuits.

Also, in the above, it is preferable that each of the protrusions beformed so as to have a substantially triangular cross section. Forexample, with the protrusions formed of a glass-cloth-containingmaterial that is normally used, the protrusions effectively and securelypass through the interlayer-insulating layer. Also, the protrusions areinserted into the metal layer that will be formed, thereby makingcharacteristics of connections between the protrusions and the metallayer to be even more secure.

Also in the invention, it is preferable that the protrusions be formedin a konide-like shape. In this case, the top of each of the protrusionscan be arranged to be planar, thereby avoiding the probability of makingheights of the protrusions to be inconsistent. In addition, according tothe protrusions, the distance (thickness) of the interlayer-insulatinglayer can be ensured to be at a constant value.

Also in the invention, it is preferable that each of the protrusions beformed in a drum-like shape. This allows the plain area of the top ofeach of the protrusions to be even larger. According to this,conductive-paste processing can be easily performed, and the reliabilityof the connection characteristics of the protrusions can also beimproved. Concurrently, effects for ensuring the distance (thickness) ofthe interlayer-insulating layer to be constant can be obtained even moresecurely.

In addition in the invention, it is preferable that a surface of each ofthe protrusions be formed in a rough pattern. Also in the invention, itis preferable that a surface of each of the protrusions be subjected toparticle-plating.

According to the above, since the surface of each of the protrusions isrough-patterned and particle-plated, connection characteristics betweenthe top thereof and the metal layer can be improved.

It is preferable that the protrusions be formed of a copper material,and the surface thereof be subjected to electrolytic chromateprocessing.

According to the above, the protrusions are formed of a copper material,and the surface thereof be subjected to electrolytic chromateprocessing. Thereby, the surface of the metal layer can be preventedfrom being oxidized, thereby allowing the reliability of the connectionbetween the protrusions and the metal layer.

It is preferable that the protrusions be arranged substantially in aplain matrix. In the stage before the conductor circuits on the twofaces are formed by selectively performing etching, whatever is themodel of the wiring circuit substrate, conductor circuits aremass-produced as standard products. Thereafter, the conductor circuitsare formed so as to differ depending upon the pattern of the model ofthe wiring circuit substrate. This method allows improvement in theproductivity of other different models of wiring circuit substrates. Inaddition, the masks need not be changed depending upon the model,thereby reducing the number of the copper-etching operations. Therefore,either the different-model small-quantity production or therestricted-model mass-production can be handled, thereby significantlycontributing to the improvement in the economy.

In addition, it is preferable that the protrusions be formed andarranged so that pressure forces exerted when the wiring circuitsubstrate is stacked are uniformed for each of the protrusions.According to this, collapsed conditions of the individual protrusionscan be uniformed, connection characteristics can be uniformed, and thereliability can be improved.

It is preferable that the protrusions be arranged so as to form a firstarea where the arrangement density is high and a second area where thearrangement density is low are formed, and dummy protrusions whoseheights are smaller than those of the protrusions be formed around thefirst area.

According to the above, the smaller dummy protrusions are arrangedaround high-density arrangement areas of the individual protrusions inaddition to the protrusions arranged at a high density. This allowsreduction in the etching rates in peripheral areas of the high-densityarrangement areas to be similar to a level of the central area. As aresult, etching rates of the protrusions can be uniformed, and also,diameters and heights of the individual protrusions can be uniformed.

Also, it is preferable that each of the protrusions include dummyprotrusions formed as a ring in its peripheral portion, and eachadjacent couple of the dummy protrusions be formed at a spacing fromeach other. According to this, improved effects of the dummy protrusionsat etching time can be obtained.

Each of the protrusions include dummy protrusions may be formed as aring in its peripheral portion. Also, it is preferable that eachadjacent couple of the dummy protrusions be formed so as to partiallyoverlap with each other. According to this, areas where the dummyprotrusions are formed can be minimized, and concurrently, the describedeffects can be obtained.

Also, it is preferable that the protrusions include a plurality of dummyprotrusions formed around one of the protrusions. According to this, theuniformity of the etching rates can further be improved.

It is preferable that the protrusions include a plurality of dummyprotrusions formed around a plurality of the protrusions, and also, theplurality of dummy protrusions be formed outside a forming area of theplurality of protrusions so as to be apart from each other at apredetermined spacing. According to this, etching rates for theplurality of protrusions can be uniformed.

It is preferable that the protrusions be formed to have a plurality ofdifferent heights. According to this, overlaying can be performedwithout causing problems on faces having different connectionmechanisms, such as stepped connection faces and faces of copper pasteand copper patterns.

It is preferable that the protrusions be formed to have a plurality ofdifferent diameters. According to this, diameters of the protrusions inwhich a high current flows can be increased, and diameters of theprotrusions in which a low current flows can be reduced. This preventsproblems such as that voltage drop occurs because a high voltage flowsin the protrusions having small diameters, joule heat is generated, andthe protrusions exclusively use unnecessarily excessive areas becausethe protrusions have large diameters while high current does not flowtherein.

It is preferable that the second metal layer have openings formed inportions corresponding to the protrusions, the diameter of each of theopenings being smaller than that of the top of each of the protrusions.

According to the above, when the protrusions are connected to the secondmetal layer, top portions of the protrusions abut the openings andcollapse them. Accordingly, strong connections between the protrusionsand the second metal layer can be ensured. This allows the reliabilityof the connections to be improved.

It is preferable that the protrusions include spacers formed of the samematerial as that for the protrusions and are formed so as to havesubstantially the same height as the protrusions. According to this,heights of the protrusions and the distance (thickness) of theinterlayer-insulating layer are arranged to be constant, therebyallowing the impedance-controllability to be improved. The spacers maybe grounded so as to be usable as an electrostatic shield.

It is preferable that the protrusions include identification marksformed of the same material as that for the protrusions and are formedso as to have substantially the same height as the protrusions.According to this, positioning and model identification can be easilycarried out.

It is preferable that a plated layer be formed around each of theprotrusions. Thus, since plating is performed before the protrusions areformed, the plating can be used as an etching mask. In addition, theplating improves the reliability of the connection of the protrusions.

Also, it is preferable that the conductive adhesion film be ananisotropic conductive film. In the above, since the anisotropicconductive film may be provided between the protrusions and the metallayer connected thereto, that is, metal particles in the anisotropicconductive film, the connection between the protrusions and the metallayer can be ensured.

It is preferable that the conductive adhesion film be formed by coatingconductive paste material as a surface treatment agent.

In this case, since the conductive paste material is coated, thecharacteristics of the connections between the protrusions and theconductor circuits can be further improved.

According to still another aspect of the present invention, a wiringcircuit substrate comprises a first metal layer for forming firstconductor circuits, an etching-barrier layer formed of a metal differingfrom that of the first metal layer on the first metal layer, protrusionsfor interconductor connection that are made of metal and are selectivelyformed on the etching-barrier layer, an interlayer-insulating layerformed on the first metal layer in a state of allowing the protrusionsto pass through, and a second metal layer that is formed on surfaces ofthe protrusions and the interlayer-insulating layer and that is used forforming second conductor circuits.

According to the above, the protrusions are selectively formed on thefirst metal layer via the interlayer-insulating layer. In this case,while erosion of the first metal layer is prevented according to theetching-barrier layer. Therefore, the base member either having at leastthe same height as that of the protrusions or a height larger than thatof the protrusions can be used to obtain the wiring circuit substrate.This reduces portions of the base member in which bending, deformation,and the like may occur during the manufacture. Also, since there is noprobability that the dimensions vary and positions of the protrusionshorizontally deviate, even when the protrusions are finely formed toincrease the arrangement density, there is no probability that defectiveinterlayer connections between the upper and lower conductor circuitsoccur because of positional deviation of the protrusions. This allowsthe yield and the reliability to be improved.

In addition, the protrusions can be formed of metal, for example, arelatively low-priced metal such as a copper material. Thereby, comparedto the conventional cases where the conductive paste formed either byfilling into the openings or printing is used as theupper-lower-conductor-circuit connecting device, the wiring circuitsubstrate can be provided at a lower price.

Also, since the protrusions are formed by selectively performing etchingfor the first metal layer, heights thereof can be uniformed. Therefore,there are no probabilities that defects in the connections between theupper and lower conductor circuits occur because of inconsistentheights. In addition, the protrusions and the first metal layer areintegrated into one unit, mechanical strengths of the protrusions can behigher than in the conventional cases.

It is preferable that the etching-barrier layer be formed so as to havethe same width of that of a section of the protrusions. When etching isperformed for the first metal layer, although the etching-barrier layerfunctions as an etching barrier, the etching is performed in a laterstep by using the protrusions as masks. Thereby, theinterlayer-insulating layer formed on the first metal layer can beformed in a good condition.

It is preferable that the etching-barrier layer be formed in an areaextending to reach reverse faces of the protrusions and theinterlayer-insulating layer. According to this, the wiring circuitsubstrate that does not require a step of etching for theetching-barrier layer can be provided. In addition, the function as anetching-barrier layer can be achieved.

In addition, it is preferable that a plated layer be formed so as tocover around the protrusions and the etching-barrier layer. According tothis, even in a wiring circuit substrate, the plating can be used as anetching mask, and also, the reliability of the connection of theprotrusions can be secured.

According to still another aspect of the present invention, a wiringcircuit substrate comprises a first wiring circuit substrate, a secondwiring circuit substrate, and a third wiring circuit substrate. Thefirst wiring circuit substrate is formed by comprising a base plate madeof insulating resin, a plurality of first metal layers that is formed onan upper surface of the base plate and that are formed of first wiringcircuits, a plurality of second metal layers that is formed on the lowersurface of the base plate and that is formed of second wiring circuits,and through-holes that are formed so as to pass through the base plateand that electrically connect the first wiring circuits on the uppersurface and the second wiring circuits on the lower surface to eachother. The second wiring circuit substrate is formed on the uppersurface of the base plate by comprising a first interlayer-insulatinglayer formed on surfaces of the base plate and the first metal layer,and a plurality of first protrusions for connecting upper and lowerconductors to each other that is selectively formed in a length so as toreach the first metal layer and the through-holes in a state of passingthrough the first interlayer-insulating layer. The third wiring circuitsubstrate is formed on the lower surface of the base plate by comprisinga second interlayer-insulating layer formed on surfaces of the baseplate and the second metal layer, and a plurality of second protrusionsfor connecting upper and lower conductors to each other that isselectively formed in a length so as to reach the second metal layer andthe through-holes in a state of passing through the secondinterlayer-insulating layer. The second wiring circuit substrate and thethird wiring circuit substrate are stacked in a state where the edges ofthe first protrusions and the second protrusions are connected to thefirst wiring circuits and the second wiring circuits. Conductive pasteis filled into the through-holes, and the second wiring circuitsubstrate and the third wiring circuit substrate are therebyelectrically connected to each other.

According to the above aspect of the invention, the through-holes areformed on the base member to electrically connect the first and secondmetal layers to each other. The first and second protrusions areprovided on the second and third wiring circuit substrate, respectively.The first and second interlayer-insulating layers are formed on faces ofthe second and third wiring circuit substrate on which the first andsecond protrusions are formed in a state of allowing the first andsecond protrusions to pass through.

In a state where the edges of the first protrusions are connected to thefirst wiring circuits formed of the first metal layer and the edges ofsecond protrusions are connected to the second wiring circuits made ofthe second metal layer, the second and third wiring circuit substratesare stacked with the first wiring circuit substrate being arrangedtherebetween, and the wiring circuit substrate is thereby configured.According to the above, high integration is can be implemented, and inaddition, improvement can be implemented for characteristics of theelectric connection between the circuit substrates and the reliabilityof the connection.

According to still another aspect of the present invention, a wiringcircuit substrate comprises a first metal layer for forming firstconductor circuits; protrusions for interlayer connection that areselectively formed on the first metal layer and that are formed of thesame metal as that for the first metal layer; an interlayer-insulatinglayer formed on a face of the first metal layer, on which theprotrusions are formed, in a state of allowing the protrusions to passthrough; a second metal layer that is formed on the protrusions and theinterlayer-insulating layer and that is used for forming secondconductor circuits; and a third metal layer arranged between the secondmetal layer and the protrusions.

According to the above aspect of the present invention, since the thirdmetal layer is provided between the protrusions and the second metallayer, the reliability of electric connection characteristics of theprotrusions is improved.

It is preferable that the second metal layer comprise openings that areformed on portions corresponding to the protrusions, each of theopenings having a diameter larger than the diameter of each of theprotrusions.

According to this, the top of each of the protrusions of the secondmetal layer is deeply inserted in a solder layer, a conductive-pastelayer, or a noble-metal film that is filled in the opening, therebyfurther improving characteristics of the connections therebetween.

Also, it is preferable that the third metal layer be formed of one of asolder layer, a conductive-paste layer, and a noble-metal film.According to this, the second metal layer and the protrusions can beconnected via one of the layers and the film, thereby allowing electricconnection characteristics therebetween to be improved.

According to still another aspect of the present invention, a wiringcircuit substrate comprises a metal layer for forming wiring circuits,an interlayer-insulating layer formed on the metal layer, protrusionsfor interconductor connection that are formed on theinterlayer-insulating layer in a state of passing through theinterlayer-insulating layer, and either conductor circuits differingfrom the conductor circuits or a circuit substrate that is formed on theprotrusions and the interlayer-insulating layer. Theinterlayer-insulating layer is formed of an anisotropic conductive film.

In the above, an anisotropic conductive film is used as aninterlayer-insulating layer. In this case, even with theinterlayer-insulating layer being arranged between the protrusions andthe metal layer, the area therebetween is allowed to become conductive;that is, the protrusions and the metal layer can securely beelectrically connected to each other.

It is preferable that an anisotropic conductive film be formed eitherbetween the protrusions and the aforementioned different conductorcircuits or between the protrusions and the circuit substrate. Thereby,the protrusions and the different conductor circuits can be securelyconnected to each other via metal particles in the anisotropicconductive film.

According to still another aspect of the present invention, a wiringcircuit substrate comprises at least two first wiring circuit substratesand a second wiring circuit substrate provided between at least twounits of the first wiring circuit substrates. Each of the first wiringcircuit substrates comprises an insulating layer having at least oneface on which first conductors of either a single layer or multiplelayers are formed and openings for securing paths for electricalconnection to the first conductor circuits are formed, aninterlayer-insulating layer formed on the one face of the insulatinglayer in which the openings are formed, and protrusions formed of aconductor-forming metal layer in a state of passing through theinterlayer-insulating layer at positions opposing the openings and areelectrically connected to the first conductor circuits through theopenings. The first wiring circuit substrates are stacked such thatfaces on each of which the protrusions and the interlayer-insulatinglayer are formed inwardly expose via the second wiring circuit substrateand are pressed. Thereby, the first wiring circuit substrates and thesecond wiring circuit substrate are integrated into one unit.

According to the invention, the protrusions electrically connected tothe first conductor circuits via the openings are provided. The twowiring circuit substrates each having the interlayer-insulating layerare stacked such that faces on each of which the protrusions and theinterlayer-insulating layer are formed inwardly expose. In this case,the two first wiring circuit substrates may be stacked either directlyor via the wiring circuit substrate and are pressed. Thereby, the wiringcircuit substrates are integrated into one unit. According to thisconfiguration, the number of layers of conductor circuits of the wiringcircuit substrate can be significantly increased, and mounting densitycan thereby be increased.

In the above, it is also preferable that the wiring circuit substratefurther comprise LSI chips individually overlaid on the first wiringcircuit substrates. In addition, it is preferable that the wiringcircuit substrate further comprise packages individually overlaid on thefirst wiring circuit substrates.

According to the invention, with either the LSI chips or the packages,the wiring circuit substrate having either the LSI chips or the packagedthat are mounted at high density can be obtained. This also allowsminiaturization to be implemented for the wiring circuit substrate.

According to still another aspect of the present invention, a wiringcircuit substrate comprises a first wiring circuit substrate, a secondwiring circuit substrate stacked on the first wiring circuit substrate,and a third wiring circuit substrate stacked on the second wiringcircuit substrate.

In this case, it is preferable that the individual first to third wiringcircuit substrates have the aforementioned various types of the wiringcircuit substrates. Thereby, the wiring circuit substrate that meetsrequirements for even higher density and even higher integration can beprovided.

In addition, the present invention defines an electronic apparatusincluding one of the wiring circuit substrate as mentioned above. Thisallows the provision of the wiring circuit substrate of the presentinvention for use in the high-integration and high-density electronicapparatus.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step offorming an etching-barrier layer on a first metal layer that will beformed to be first conductor circuits, and forming a second metal layer,which is used to form protrusions, on the etching-barrier layer, theetching-barrier layer being formed of a metal differing from that of thefirst metal layer; a step of forming the protrusions by selectivelyperforming etching for the second metal layer by using etchant that doesnot etch at least the etching-barrier layer; a step of removing theetching-barrier layer by using the protrusions as masks and by usingetchant that does not etch the first metal layer; a step of forming aninterlayer-insulating layer on a face of the first metal layer on whichthe protrusions are formed; and a step of forming a third metal layer,which will be formed to be second conductor circuits, on theinterlayer-insulating layer and the protrusions.

According to the above aspect, etching is selectively performed for thesecond metal layer for forming the protrusions by using etchant thatdoes not etch the etching-barrier layer. Thereby, the protrusions can beforming, and only the etching-barrier layer can be removed by usingetchant and by using the protrusions as masks. The protrusions connectthe first and second conductor circuits to each other. Thus, theaforementioned wiring circuit substrate can be obtained.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step offorming an etching-barrier layer on a first metal layer that will beformed to be first conductor circuits, and forming a second metal layer,which is used to form protrusions, on the etching-barrier layer, theetching-barrier layer being formed of a metal differing from that of thefirst metal layer; a step of forming the protrusions by selectivelyperforming etching for the second metal layer by using etchant that doesnot etch at least the etching-barrier layer; a step of forming aninterlayer-insulating layer on a face of the first metal layer on whichthe protrusions are formed; a step of forming a third metal layer, whichwill be formed to be second conductor circuits, on theinterlayer-insulating layer and the protrusions; and a step of removingthe first metal layer and the etching-barrier layer by performingselective etching using an etching mask layer as a mask.

According to the invention, selective etching by using the protrusionsas masks is not performed for the etching-barrier layer. Specifically,the etching is performed for the etching-barrier layer together with thefirst metal layer for which selective etching is performed. This avoidsa step that is carried out only to remove unnecessary portions of theetching-barrier layer, thereby allowing the manufacturing steps to bereduced.

Also in the invention, the step of forming the protrusions may include astep of using a fourth metal layer as an etching mask. It is preferablethat the manufacturing method further comprise a step of allowing thefourth metal layer to remain and covering faces of the protrusions byusing the fourth metal layer.

According to above, when etching is selectively performed for a layermade of a base metal to form the protrusions, the fourth metal layer isused as an etching mask. Even after the protrusions is formed, thefourth metal layer is allowed to remain, and the fourth metal layer isused to cover all the surfaces of the protrusions. In this case, withoutperforming a difficult operation of coating conductive paste on the topof each of the protrusions, the fourth metal layer used as the etchingmask can be used as a means for improving characteristics of theconnection between the individual protrusions and the second metallayer.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step offorming an etching-barrier layer on a first metal layer that will beformed to be first conductor circuits, and forming a second metal layer,which is used to form protrusions, on the etching-barrier layer, theetching-barrier layer being formed of a metal differing from that of thefirst metal layer; a step of forming the protrusions by selectivelyperforming etching for the second metal layer by using etchant that doesnot etch at least the etching-barrier layer; a step of removing theetching-barrier layer by using the protrusions as masks and by usingetchant that does not etch the first metal layer; forming aninterlayer-insulating layer on a face of the first metal layer on whichthe protrusions are formed and forming a multilayer body; a step offorming a third metal layer, which will be formed to be second conductorcircuits, on the interlayer-insulating layer and the protrusions; a stepof overlaying individual metal foils on the third metal layer and thefirst metal layer of the wiring circuit substrate and performingpressing-heating processing therefor; and a step of selectivelyperforming for the third metal layer and the metal foils and therebyforming the second conductor circuits, and also, selectively performingetching for the first metal layer and the metal foils and therebyforming the first conductor circuits, thereby forming the wiring circuitsubstrate.

According to the present invention, the wiring circuit substrate andmetal foils are overlaid, and etching is selectively performed for boththe first metal layer and the metal foils at the same time. This allowsthe provision of the wiring circuit substrate in which the first andsecond conductor circuits interlayer-insulated by theinterlayer-insulating layer are provided on two faces, and the first andsecond conductor circuits are electrically connected to each other viathe protrusions that pass through the interlayer-insulating layers.

Also, the manufacturing method may further comprise a step of stackingat least two units of the multilayer bodies on two faces of the wiringcircuit substrate, on which the first conductor circuits and the secondconductor circuits are formed, so as to be as a sandwich in a statewhere one face of each of the multilayer bodies faces inward, andperforming pressing/heating processing therefor, thereby making anintegral unit; and a step of selectively performing etching for twoconductor-forming metal layers positioned on two faces of the integralunit, thereby forming conductor circuits on the two faces.

According to the above, at least two units of the multilayer body areoverlaid on two faces of the wiring circuit substrate and arepress-heated, and they are thereby integrated into one unit. Then,etching is selectively performed for the metal layers existing on twofaces of the integral unit, thereby forming the conductor circuits ontwo faces thereof. Accordingly, the wiring circuit substrate havingconductor circuits of four layers can be obtained.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step offorming an insulating layer including openings on at least one face ofconductor circuits of either a single layer or multiple layers; a stepof forming protrusions that are formed of a conductor-circuit-formingmetal layer at positions opposing the openings and are electricallyconnected to the conductor circuits through the openings; a step offorming at least two wiring circuit substrates having aninterlayer-insulating layer formed on the side of the insulating layerwhere the protrusions are formed; a step of stacking and pressing atleast two units of the wiring circuit substrates directly or via anotherwiring circuit substrate in a state where the sides where theprotrusions and the interlayer-insulating layer are formed face inward,thereby making them into an integral unit.

According to the above, there is provided a base metal via theinsulating layer having the openings in one main face of the conductorcircuits of either a single layer or multiple layers. Also, there areprovided the protrusions electrically connected to the conductorcircuits through the openings. The two wiring circuit substrates havingthe interlayer-insulating layer formed on the side of the insulatinglayer where the protrusions are formed are stacked directly or viaanother wiring circuit substrate in a state where the sides where theprotrusions and the interlayer-insulating layer are formed face inward,thereby making them into an integral unit. Thereby, the number of thelayers of the conductor circuits of the wiring circuit substrate can besignificantly increased, and the mounting density can therefore beincreased.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step ofpreparing a first metal layer used for forming first conductor circuitsand selectively forming mask films on one face of the first metal layer;a step of performing half-etching for the first metal layer by using themask films as masks, thereby selectively forming protrusions on the oneface of the first metal layer; a step of forming aninterlayer-insulating layer on the first interlayer-insulating layer ina state of allowing the protrusions to pass through; a step ofoverlaying a second metal layer, which will be formed to be secondconductor circuits, on the protrusions and the interlayer-insulatinglayer; and a step of selectively patterning the first metal layer andthe second metal layer at one time or different times, thereby formingthe first conductor circuits and the second conductor circuits.

According to the invention, mask films are selectively formed on oneface of the first metal layer that is used as a base member, andhalf-etching is performed for the first metal layer by using the maskfilms as masks. Subsequently, the metal layer to be formed to be theconductor circuits and the protrusions are formed. Then, the two metallayers are formed via the interlayer-insulating layer on the surface ofthe first metal layer (which will be formed to be the first conductorcircuits) on which the protrusions are formed. Subsequently, the firstand second metal layers formed on two surfaces of theinterlayer-insulating layer are selectively patterned at one time ordifferent times, thereby forming wiring films. Thereby, the wiringcircuit substrate can be obtained.

It is preferable that the manufacturing method further comprise a stepof forming an anisotropic conductive film on the top of each of theprotrusions before overlaying the second metal layer. The anisotropicconductive film improves electrical-connection characteristics betweenthe second metal layer and the protrusions.

It is also preferable that the manufacturing method further comprise astep of performing spray-etching for the top of each of the protrusionsafter forming the protrusions. This allows the surfaces of each of theprotrusions to have a rough pattern.

It is preferable that the step of forming the protrusions include a stepof using resist masks each having a diameter smaller than a diameter ofeach of the protrusions required to be formed, thereby performinghalf-etching. This allows spear-like protrusions to be formed.

Also, it is preferable that the step of forming the protrusions includea step of removing the masks after forming the protrusions by performingthe half-etching, and a step of performing half-etching again. Thisallows spear-like protrusions to be formed.

Also, it is preferable that said manufacturing further comprise a stepof removing unnecessary pieces of the protrusions by performingover-etching before performing patterning for the firs conductorcircuits and the second conductor circuits. This allows the protrusionsto be arranged and arrayed as desired. This is effective when theprotrusions are formed in an arrangement from a state of a matrix-likearrangement so as to receive uniformed pressure.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step offorming a plurality of first metal layers formed of first wiringcircuits on an upper surface of a base plate made of insulating resin,and forming a plurality of second metal layers formed of second wiringcircuits on a lower surface of the base plate. The manufacturing methodalso comprises a step of forming first protrusions and a firstinterlayer-insulating layer in a length so as to reach the first metallayer in a preliminarily arranged state where the first protrusions passthrough the first interlayer-insulating layer, and forming secondprotrusions and a second interlayer-insulating layer in a length so asto reach the second metal layer in a preliminarily arranged state wherethe second protrusions pass through the second interlayer-insulatinglayer. The manufacturing method also comprises a step of fillingconductive paste, which electrically connects the first wiring circuitson the upper surface and the second wiring circuits on the lower surfaceto each other, into through-holes formed so as to pass through the baseplate. In addition, the manufacturing method comprises a method ofoverlaying the first interlayer-insulating layer on surfaces of the baseplate and the first metal layer (that is, on the upper surface of thebase plate), and connecting the first protrusions to the first metallayer; and overlaying the second interlayer-insulating layer on surfacesof the base plate and the second metal layer (that is, on the lowersurface of the base plate), and connecting the second protrusions to thesecond metal layer. The step of connection to the first metal layerincludes a step of allowing the first protrusions to abut openingsformed in the first metal layer to have a diameter smaller than that ofthe top of each of the first protrusions. Also, the step of connectionto the second metal layer includes a step of allowing the secondprotrusions to abut openings formed in the second metal layer to have adiameter smaller than that of the top of each of the second protrusions.

According to the invention, when the first and second protrusions areconnected to the first and second metal layers, the top of the first andsecond protrusions abut each of the openings and collapses it. Thisfurther increases the strengths of connections between the first andsecond protrusions and the first and second metal layers, therebyallowing the reliability of the connections.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step ofarranging many protrusions, which are formed of metal for interconductorconnection, on a surface of a first metal layer; a step of providing aninterlayer-insulating layer on the surface of the first metal layer in astate of allowing the protrusions to pass through; a step of forming asecond metal layer on surfaces of the interlayer-insulating layer andthe protrusions, the second metal layer being formed of a metaldiffering from that of the first metal layer; and a step of formingspacers using the same material as that for the protrusions so as tohave substantially the same heights as the protrusions at the same stepof forming the protrusions.

According to the above, the spacers are formed in the same step as thatof forming the protrusions. Therefore, without increasing the number ofsteps, by the provision of the spacers, the wiring circuit substrate canbe formed that allows spacings to be secured between the spacers and themetal layers.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate, comprises a step ofarranging many protrusions, which are formed of metal for interconductorconnection, on a surface of a first metal layer; a step of providing aninterlayer-insulating layer on the surface of the first metal layer in astate of allowing the protrusions to pass through; forming a secondmetal layer on surfaces of the interlayer-insulating layer and theprotrusions, the second metal layer being formed of a metal differingfrom that of the first metal layer; and a step of forming identificationmarks using the same material as that for the protrusions so as to havesubstantially the same heights as the protrusions at the same step offorming the protrusions.

According to the above, the identification marks can be formed in thesame step as that of forming the protrusions. Therefore, withoutincreasing the number of steps, the wiring circuit substrate having theidentification marks can be obtained.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate, comprises a step offorming a plurality of first metal layers formed of first wiringcircuits on an upper surface of a base plate made of insulating resin,and forming a plurality of second metal layers formed of second wiringcircuits on a lower surface of the base plate. The manufacturing methodalso comprises a step of forming first protrusions and a firstinterlayer-insulating layer in a length so as to reach the first metallayer in a preliminarily arranged state where the first protrusions passthrough the first interlayer-insulating layer, and forming secondprotrusions and a second interlayer-insulating layer in a length so asto reach the second metal layer in a preliminarily arranged state wherethe second protrusions pass through the second interlayer-insulatinglayer. Also, the manufacturing method comprises a step of overlaying thefirst interlayer-insulating layer on surfaces of the base plate and thefirst metal layer (that is, on the upper surface of the base plate), andconnecting the first protrusions to the first metal layer; and a step ofoverlaying the second interlayer-insulating layer on surfaces of thebase plate and the second metal layer (that is, on the lower surface ofthe base plate), and connecting the second protrusions to the secondmetal layer. The manufacturing method also comprises a step of forming athird metal layer, which is formed of either conductive paste or a noblemetal, on surfaces of the first metal layer and the second metal layerbefore the aforementioned connection is performed.

According to the invention, the first and second wiring circuits can beassembled with the base plate being arranged therebetween. In theassembly, since the individual first and second protrusions areconnected to each other via the third metal layer (one of conductivepaste and a noble-metal film), electric connection characteristicstherebetween can be in a suitable condition.

Also, it is preferable that the manufacturing method further comprise astep of removing partial areas of the third metal layer that protrudefrom surfaces of the first metal layer and the second metal layer bypolishing the surfaces of the first metal layer and the second metallayer after the third metal layer is formed. According to this, thethird metal layer can be formed only in, for example, the openings inthe first and second metal layers.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate, comprises a step ofselectively forming protrusions for interconductor connection on a firstmetal layer, the protrusions being formed of the same material as thatfor the first metal layer; a step of forming an interlayer-insulatinglayer on a surface of the first metal layer on which the protrusions areformed; and a step of forming a second metal layer, which is formed tobe second conductor circuits, on the interlayer-insulating layer and theprotrusions. Also, the manufacturing method comprises a step of formingone of a solder layer, a conductive-paste layer, and a noble-metal filmbetween the protrusions and the second metal layer so as to correspondto the protrusions; and a step of stacking the wiring circuit substrateby connecting the protrusions to one of the solder layer,conductive-paste layer, and the noble-metal film.

According to the invention, before the second metal layer is formed, oneof the solder layer, the conductive-paste layer, and the noble-metallayer is formed so as to be overlaid on surfaces of the protrusions.According to this arrangement, high integration is achieved in theassembly, and concurrently, the wiring circuit substrate improvingelectric connection characteristics between the circuit substrates andthe reliability of connections can be obtained.

According to still another aspect of the present invention, amanufacturing method for a wiring circuit substrate comprises a step ofselectively forming protrusions for interconductor connection on a firstmetal layer, the protrusions being formed of the same material as thatfor the first metal layer. The manufacturing method also comprises astep of forming an interlayer-insulating layer on a surface of the firstmetal layer on which the protrusions are formed; and a step of forming asecond metal layer, which is formed to be second conductor circuits, onthe interlayer-insulating layer and the protrusions. In addition, themanufacturing method comprises a step of printing one of a solder layer,a conductive-paste layer, and a noble-metal film between the protrusionsand the second metal layer so as to correspond to the protrusions; and astep of stacking the wiring circuit substrate by connecting theprotrusions to one of the solder layer, conductive-paste layer, and thenoble-metal film. The step of stacking the wiring circuit substrateincludes a step of forming the configuration wherein each of theprotrusions passes through the interlayer-insulating layer, and one ofthe solder layer, the conductive-paste layer, and the noble-metal filmis connected to the protrusions.

According to the invention, the second metal layer that will be formedto be the second conductor circuits differing from the first conductorcircuits are formed on the side where the protrusions are formed. Then,corresponding to the protrusions, a member on which one of the solderlayer, the conductive-paste layer, and the noble-metal layer is overlaidis provided. Thereby, the wiring circuit substrate can be obtained.

Another aspect of the present invention includes a base member, and alaminating sheet to be laminated on one or both surfaces of the basemember. The base member has an insulating layer and metal wiring layersformed on both surfaces of the insulating layer. Furthermore, the basemember has one or a plurality of through holes formed through the metalwiring layers and the insulating layer. Moreover, the base member hasone or a plurality of conductive members formed so as to fill the one orthe plurality of the through holes. The laminating sheet has a wiringlayer, and one or a plurality of protrusion parts formed, projectingfrom the wiring layer at a position facing to the one or the pluralityof the through holes. Furthermore, the laminating sheet is laminated inthe state with the one or the plurality of the protrusion parts and theone or the plurality of the conductive materials connected.

In the present invention, the laminating sheet is formed on one or bothsurfaces of the base member. At the time, since the protrusion part isconnected so as to cut into the conductive material, the wiring layercomprising the laminating sheet cannot be deflected also in the vicinityof the through hole. Therefore, the film thickness can be evened at anecessary thickness, and thus minute wiring can be enabled.

Moreover, since the protrusion part and the conductive material areconnected directly, the adhesion property can be strengthened, and thusthe reliability of the inter-layer connection can be improved.Furthermore, unlike the conventional example, the wiring layer needs notbe formed by an electroless plating and a subsequent electrolyticplating of a copper film.

Still another aspect of the present invention includes a base member, afirst laminating sheet to be laminated on one or both surfaces of thebase member, and a second laminating sheet to be laminated outside thefirst laminating sheet. The base member has an insulating layer andmetal wiring layers formed on both surfaces of the insulating layer.Furthermore, the base member has one or a plurality of through holesformed through the metal wiring layers and the insulating layer.Moreover, the base member has one or a plurality of conductive membersformed so as to fill the one or the plurality of the through holes. Thefirst laminating sheet has a wiring layer, and one or a plurality ofprotrusion parts formed, projecting from the wiring layer at a positionfacing to the one or the plurality of the through holes. Furthermore,the first laminating sheet is laminated in the state with the one or theplurality of the protrusion parts and the one or the plurality of theconductive materials connected.

According to the present invention, since the second laminating sheet isfurther laminated, a multi-layer structure of the wiring substrate canbe provided by a relatively simple process.

Still another aspect of the present invention has a base memberincluding metal wiring layers formed on both surfaces of an insulatinglayer, and one or a plurality of through holes formed through the metalwiring layers and the insulating layer. A step of filling the one or theplurality of the through holes of the base member with the one or theplurality of the conductive materials is included. Furthermore, alaminating sheet including one or a plurality of protrusion partsformed, projecting from the metal layer at a position facing to themetal layer and the one or the plurality of the through holes isprovided. A step of laminating the laminating sheet on one or bothsurfaces of the base member in the state with the one or the pluralityof the protrusion parts and the one or the plurality of the conductivematerials connected is included. Moreover, a step of forming a wiringlayer by patterning the metal layer of the laminating sheet is provided.

Furthermore, still another aspect of the present invention has a basemember including metal wiring layers formed on both surfaces of aninsulating layer, and one or a plurality of through holes formed throughthe metal wiring layers and the insulating layer. A step of filling theone or the plurality of the through holes of the base member with theone or the plurality of the conductive materials is included.Furthermore, a laminating sheet including one or a plurality ofprotrusion parts formed, projecting from the wiring layer at a positionfacing to the wiring layer and the one or the plurality of the throughholes is provided. A step of laminating the laminating sheet on one orboth surfaces of the base member in the state with the one or theplurality of the protrusion parts and the one or the plurality of theconductive materials connected is included. Moreover, a step of furtherforming one or a plurality of laminating sheets substantially same asthe laminating sheet on the surface of the laminating sheet is included.

According to the present invention, a multi-layer structure of thewiring substrate can be provided by a relatively simple process ofpreparing a base member and a laminating sheet, selective etchingnecessary for forming a wiring layer, and laminating the laminatingsheet and the base member.

Moreover, by increasing the number of the laminating sheets to belaminated, a multi-layer structure of the wiring circuit substrate caneasily be achieved so that a further high integration of the wiringcircuit substrate can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is cross-sectional views showing example manufacturing steps foran example wiring circuit substrate according to the present invention;

FIGS. 1B to 1G are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 2A to 2D are cross-sectional views showing example manufacturingsteps for an example according to a first embodiment;

FIGS. 3A to 3F are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 4A to 4C are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 5A to 5G are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 6A and 6B are cross-sectional views showing example manufacturingsteps for an example according to a fifth embodiment;

FIGS. 7A to 7H are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 8A to 8C are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 9A to 9E are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate according to the presentinvention;

FIGS. 10A and 10B are cross-sectional views individually showingdifferent example protrusions of an example wiring circuit substrateaccording to the present invention;

FIG. 11 is a perspective view of a main portion of an embodiment whereinprotrusions of a wiring circuit substrate of the present invention arearranged at individual cross sections in a matrix;

FIG. 12 is a perspective view of an embodiment of an arrangement whereineach protrusion receives a uniformed pressure exerted when an examplewiring circuit substrate of the present invention is stacked;

FIG. 13 is a cross-sectional view an embodiment wherein dummyprotrusions are provided to uniform etching rates in order to uniformheights and diameters of protrusions for connecting upper and lowerconductors of an example wiring circuit substrate according to thepresent invention;

FIGS. 14A to 14D are plan views of individual embodiments wherein dummyprotrusions are provided;

FIG. 15 is a cross-sectional view of an embodiment wherein protrusionsindividually having different heights of an example wiring circuitsubstrate of the present invention are arranged so as to correspond to astepped connection face;

FIG. 16A is a perspective view of an embodiment wherein spacers that areformed of the same material as the protrusions of an example wiringcircuit substrate of the present invention and that have the sameheights as those thereof;

FIG. 16B is a cross-sectional view of an embodiment wherein spacers thatare formed of the same material as the protrusions of an example wiringcircuit substrate of the present invention and that have the sameheights as those thereof;

FIG. 17 is a cross-sectional view of an embodiment of protrusions of anexample wiring circuit substrate of the present invention, whereinprotrusions having different diameters are arranged;

FIG. 18A is a perspective view of an embodiment of the presentinvention, wherein identification marks formed of the same material asthat of protrusions are provided;

FIG. 18B is a plan view of an example the identification mark in FIG.18A;

FIG. 18C is a plan view of another example of the identification mark inFIG. 18A;

FIGS. 19A to 19D are cross-sectional views showing example manufacturingsteps for an example wiring circuit substrate of the present invention;

FIG. 20A is a cross-sectional view of an example configuration whereinan opening having a diameter larger than that of the top of each ofprotrusions is formed in a portion corresponding to the protrusion of aconductor circuit;

FIG. 20B is a plan view showing the shape of a portion to which aprotrusion of a conductor circuit is connected;

FIG. 20C is a cross-sectional view showing an example state wherein,after one of a conductive-paste layer, a solder layer, and a noble-metallayer is formed, the surface is polished to remove a portion of thelayer on a conductor circuit, thereby allowing the conductive paste, thesolder, or the noble metal to remain only in an opening;

FIGS. 21A to 20C are cross-sectional views of example manufacturingsteps of an example wiring circuit substrate according to the presentinvention;

FIG. 22 is a cross-sectional view of an embodiment using an anisotropicconductive film as an interlayer-insulating layer of an example wiringcircuit substrate according to the present invention;

FIGS. 23A to 23C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 24A to 24C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 25A to 25C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 26A to 26C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 27A to 27C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIG. 28 is a cross-sectional view of an example wiring circuitsubstrates to be stacked;

FIGS. 29A to 29C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 30A to 30C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 31A to 31C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 32A to 32C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 33A to 33C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIG. 34 is a cross-sectional view of an example wiring circuitsubstrates of the present invention to be stacked;

FIGS. 35A to 35C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 36A to 36C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 37A to 37C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 38A to 38C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIG. 39 is a cross-sectional view of an example wiring circuitsubstrates of the present invention to be stacked;

FIGS. 40A to 40C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 41A to 41C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 42A to 42C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIGS. 43A to 43C are cross-sectional views of example wiring circuitsubstrates of the present invention that are to be stacked and/or thatare stacked;

FIG. 44 is a perspective view of an example stacked wiring circuitsubstrate according to the present invention;

FIG. 45 is a block diagram of an example electronic apparatus includingwiring circuit substrates according to the present invention;

FIGS. 46A to 46D are cross-sectional views showing an embodiment ofproduction steps of a wiring circuit substrate according to the presentinvention.

FIGS. 47A to 47C are cross-sectional views showing an embodiment ofproduction steps of a wiring circuit substrate according to the presentinvention.

FIGS. 48A to 48C are cross-sectional views showing an embodiment ofproduction steps of a base member of a wiring circuit substrateaccording to the present invention.

FIGS. 49A to 49D are cross-sectional views showing an embodiment ofproduction steps of a base member of a wiring circuit substrateaccording to the present invention.

FIGS. 50A to 50D are cross-sectional views showing an embodiment ofproduction steps of a laminating sheet of a wiring circuit substrateaccording to the present invention.

FIGS. 51A to 51D are cross-sectional views showing an embodiment ofproduction steps of a laminating sheet of a wiring circuit substrateaccording to the present invention.

FIGS. 52A to 52F are cross-sectional views showing an embodiment ofproduction steps of a laminating sheet of a wiring circuit substrateaccording to the present invention.

FIGS. 53A to 53C are cross-sectional views showing an embodiment ofproduction steps of a wiring circuit substrate according to the presentinvention.

FIGS. 54A to 54F are cross-sectional views used to explain aconventional example of a high-density-mounting wiring circuitsubstrate, and shows a manufacturing method of the wiring circuitsubstrate in the order of steps (A) to (F);

FIGS. 55A to 55C are cross-sectional views sequentially showingmanufacturing steps (G) to (I) for the aforementioned conventionalexample of the wiring circuit substrate; and

FIGS. 56A to 56G are cross-sectional views used to explain anotherconventional example of a high-density-mounting wiring circuitsubstrate, and shows a manufacturing method in the order of steps (A) to(G).

FIGS. 57A to 57E are cross-sectional views showing a conventionalproduction steps of a wiring circuit substrate.

FIGS. 58A to 58D are cross-sectional views showing a conventionalproduction steps of a wiring circuit substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinbelow, a detailed description will be given of preferredembodiments of the present invention with reference to the accompanyingdrawings.

First Embodiment

First of all, a description will be given of a configuration and anoutline of a wiring circuit substrate according to a first embodiment ofthe present invention. The description will be made according to thesequential manufacturing steps. FIGS. 1A to 1G and 2A to 2D arecross-sectional views each showing the wiring circuit substrate and amanufacturing method therefor according to the present invention in theorder of manufacturing steps.

Step (A)

As shown in FIG. 1A, a base member 20 (for example, glass epoxy prepare)is prepared. The base member 20 is composed of materials including acopper foil 21, an etching-barrier layer 22, and a copper foil 23. Thecopper foil 21 (protrusion-forming metal layer) is used for formingprotrusions and has a thickness of, for example, 100 μm. Theetching-barrier layer 22 has a thickness of, for example, 2 μm, is madeof, for example, a nickel plated layer, and is formed on the entiresurface of the copper foil 21. The copper foil 23(conductor-circuit-forming metal foil having a thickness of, forexample, 18 μm) is formed on the surface of the etching-barrier layer22.

Thus, the etching-barrier layer 22 is plated and formed on the copperfoil 21, and the copper foil 23 covers the etching-barrier layer 22.

Step (B)

Subsequently, as shown in FIG. 1B, a resist film 24 is selectivelyformed on the surface of the aforementioned protrusion-forming copperfoil 21. The resist film 24 is formed so as to cover portions on whichprotrusions are formed.

Step (C)

Subsequently, etching is performed for the aforementioned copper foil 21by using the aforementioned resist film 24 as a mask, thereby formingprotrusions 25. For the etching, wet etching is performed using etchantthat does not etch the etching-barrier layer 22, but is capable ofetching the copper foil 21.

Step (D)

Subsequently, the resist film 24 used as the etching mask in the etchingis removed. FIG. 1D illustrates a state where the etching mask has beenremoved.

Step (E)

Subsequently, as shown in FIG. 1E, etching is performed for theaforementioned etching-barrier layer 22 by using the protrusions 25 asmasks. The etching in this step uses etchant (nickel-parting liquid)that does not etch a metal (copper in the present embodiment) thatcomposes the protrusions 25, but capable of etching a metal (nickel inthe present embodiment) that composes the etching-barrier layer 22.

Step (F)

Subsequently, as shown in FIG. 1E, thin conductive paste 26 is appliedon the top portion (upper portion) of each of the protrusions 25, andthereafter, cures it. This step is not mandatory; however, it allowssignificant improvement in reliability of the connection between each ofthe protrusions 25 and the copper foil.

Step (G)

Subsequently, an insulating sheet is press-bonded using a heating rolleronto the faces on which the aforementioned protrusions 25 formed of theaforementioned copper foil 21. Thereby, as shown in FIG. 1G, aninterlayer-insulating layer 27 is formed. In this case, for theinterlayer-insulating layer 27, an insulation layer thinner than theheight of the protrusion 25 (height including the thickness of theconductive paste 26 when the conductive paste 26 is applied) isselectively used so that the upper portion of the protrusion 25protrudes as the insulating sheet. Otherwise, interlayer connectionusing the protrusions 25 cannot be securely performed. According to stepG described above, the interlayer-insulating layer 27 is formed on thecopper foil 23. Thus, the protrusions 25 are connected via the copperfoil 23 and the etching-barrier layer 22 and pierce it so as to protrudetherefrom, and a multilayer body 28A is thereby composed. This step isperformed at a temperature at which the epoxy resin softens, andimmediately, the temperature is returned to a room temperature so thatcuring reaction does not occur in the epoxy.

Steps (H) and (I)

Subsequently, as shown in FIG. 2A, the interlayer-insulating layer 27 ofthe aforementioned multilayer body 28 is formed; and a copper foil(conductor-forming metal layer) having a thickness of, for example, 18μm is placed on the side where the protrusions 25 protrude, is thermallypress-bonded, and is thereby overlaid using an overlaying press. By thisstep, a multilayer body is 30A is composed in which the metal layer 23and a metal layer 29 that are formed on the interlayer-insulating layer27 are interlayer-connected via the protrusions 25.

Steps (J) and (K)

Subsequently, as shown in FIG. 2C, resist films 24 to be used as etchingmasks are formed on the surfaces of the metal layers 23 and 29.Thereafter, etching is performed for the metal layers 23 and 29 by usingthe resist films 24 as masks, and conductor circuits 31 and 32 arethereby formed. A wiring circuit substrate 33 as shown in FIG. 2D isthereby produced, in which the conductor circuits 31 and 32 on twosurfaces are interlayer-connected via the protrusions 25. The circuitsubstrate 33 thus formed is the first embodiment of the wiring circuitsubstrate according to the present invention.

As described above, according to the first embodiment, processing isstarted by using the base member 20 including at least the copper foil21, which is the protrusion-forming metal layer having a thickness (forexample, 50 to 200 μm) that is sufficient for composing the protrusions25. Therefore, the embodiment has advantages in that defects such asdeformation are not easily caused, and dimensional accuracy is stable.Because of the stable dimensional accuracy, positional deviation doesnot occur in the protrusions 25 after they are formed. This preventsproblems as occurred in the conventional example. For example, thepresent embodiment prevents the problem that since conductive paste 3(through-hole) in the opening 2 in the conventional example shown inFIGS. 23 and 24 causes positional deviation, necessary connectionbetween the upper and lower conductor circuits 5 cannot be made.Accordingly, in the present embodiment, the protrusions 25 each having avery small diameter can be arranged at high accuracy. In addition, theultra-high-density circuit substrate 33A in which interlayer connectionbetween conductor circuits is ensured can be obtained.

Furthermore, the protrusions 25 are formed of, for example, the copperfoil 21, material costs required for forming can be low. Even in a casewhere the arrangement density of the protrusions 25 is increased and thenumber of the arrangements is increased, the cost for the wiring circuitsubstrate is not increased. This is different from the conventional casewhere the cost is increased because of use of the conductive pastemainly made of a noble metal, such as silver. This significantlycontributes to the reduction in the cost for the wiring circuitsubstrate.

In addition, since the protrusions 25 are formed by selectivelyperforming etching for the copper foil 21, the height of each of theprotrusions 25 is determined according to the thickness of the copperfoil 21. In this case, since the copper foil 21 can be produced so as tohave the thickness at very high uniformity, the heights of theprotrusions 25 can be uniformed. Therefore, the present embodiment doesnot arise problems such as a possibility that heights of the protrusions11 become ununiform due to formation of the protrusions 11 withconductive paste through printing, as in the conventional art shown inFIG. 46 and FIG. 47 and a possibility that the upper portion is recessedbecause of volatilization of solvent during curing of the conductivepaste 3, thereby causing incomplete connection to be made between theupper and lower conductor circuits. Accordingly, in the presentembodiment, although the protrusions 25 are miniaturized and are formedat high density, secure connection between the upper and lower conductorcircuits can be expected, and improvement in the reliability and theyield can therefore be implemented.

Second Embodiment

Hereinbelow, a description will be given of a second embodimentaccording to the present invention with reference to FIGS. 3A to 3F. Thesecond embodiment includes configurations and processing steps that aresubstantially common to those in the first embodiment. FIGS. 3A to 3Fare cross-sectional views showing a manufacturing method for a wiringcircuit substrate according to the second embodiment of the presentinvention in the order of manufacturing steps.

Step (A)

The same steps shown in FIGS. 1A to 1D are performed, thereby making thesubstrate in the state where protrusions 25 are formed. FIG. 3A showsthe state where the protrusions 25 are formed.

Step (B)

Subsequently, as shown in FIG. 3B, depending on the requirement, thinconductive paste 26 is applied on the top portion (upper portion) ofeach of the protrusions 25, and thereafter, cures it. This step is notmandatory; however, it allows significant improvement in reliability ofthe connection between each of the protrusions 25 and a copper foil thatwill be formed in a later step.

In step (B), a step of removing an etching-barrier layer 22 for whichetching is carried out using protrusions 25 as masks is not performed.

As will be described below, unnecessary portions of the etching-barrierlayer 22 will be removed in performing selective etching for a metallayer 23. Specifically, when patterning is performed to form conductorcircuits, etching for the etching-barrier layer 22 is performed at thesame time when etching is performed for the metal layer 23. This is acharacteristic aspect that is different from the above-described firstembodiment.

Step (C)

Subsequently, as shown in FIG. 3C, an interlayer-insulating layer 27 isformed, thereby forming a multilayer body 28 at a completion time. Themultilayer body 28 includes the metal layer 23, the etching-barrierlayer 22 formed on the metal layer 23, the plurality of protrusions 25provided on the etching-barrier layer 22, conductive paste 26 providedon the top portion of each of the protrusions 25, and theinterlayer-insulating layer 27 formed between the protrusions 25.

Step (D)

Subsequently, as shown in FIG. 3D, a copper foil 29 (conductor-formingmetal layer) is thermally press-bonded and thereby overlaid on themultilayer body 28 by using an overlaying press. Thereby, a multilayerbody 30 is formed. The multilayer body 30 is formed in a state where themetal layers 23 and 29 formed on two faces of the interlayer-insulatinglayer 27 are interlayer-connected via the protrusions 25.

Step (E)

Subsequently, as shown in FIG. 3E, resist films 24 to be used as etchingmasks are formed on the surface of the metal layer 23. Similarly, theresist films 24 to be used as etching masks are formed on the surface ofthe metal layer 29.

Thereafter, etching is performed for the metal layers 23 and 29 by usingthe resist films 24 as masks, and conductor circuits 31 are therebyformed. Similarly, etching is performed for the metal layer 29 by usingthe resist films 24 as masks, and conductor circuits 32 are therebyformed.

Furthermore, simultaneously the etching-barrier layer 22 in the regioncontacting with the metal layer 23 is also etched by this etchingprocess. Preferably, the etching-barrier layer 22 is formed of, forexample, a nickel material.

The conductor circuits 31 and 32 on two faces are interlayer-connectedto each other via the protrusions 25. The wiring circuit substrate 33 isthus produced.

Step (F)

As shown in FIG. 3F, the resist films 24 used as etching masks areremoved. The wiring circuit substrate 33 after the removal of the resistfilm 24 is the second embodiment of the present invention.

For etching to be performed by using the resist films 24 in areas wherethe conductor circuits 31 and 32 are formed, etchant described below ispreferably used. The preferable etchant is capable of etchingnickel-based metals as well as copper-based metals. With the etchant ofthe aforementioned type being used, the etching-barrier layer 22 (forexample, a nickel layer) and the metal layer 23 (for example, a copperlayer) can be removed by performing selective etching using the resistfilms 24 as masks. According to the above, after the protrusions 25 areformed, the etching-barrier layer 22 need not be masked for removal.This allows reduction in steps to be implemented.

As described above, according to the second embodiment, while the sameadvantages as those in the first embodiment, both the etching-barrierlayer 22 and the metal layer 23 can be removed by performing single-timeselective etching using the same resist films 24 as masks.

Accordingly, compared to the first embodiment, the number of steps canbe fewer.

Third Embodiment

Hereinbelow, a description will be given of a third embodiment accordingto the present invention with reference to FIGS. 4A to 4C.

The third embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment. FIGS. 4A to4C are cross-sectional views showing a manufacturing method for a wiringcircuit substrate according to the third embodiment of the presentinvention in the order of manufacturing steps.

The third embodiment is described with reference to an example in whichthe multilayer bodies 28 formed in step (G) of the first embodiment areoverlaid on the two faces of the wiring circuit substrate 33manufactured in the first embodiment. After the multilayer bodies 28 areoverlaid, selective etching is performed for the metal layers 23 in theindividual multilayer bodies 28A, patterning is performed therefor, andconductor circuits are thereby formed. This allows the provision ofmultilayer conductor circuits, for example, four-layer conductorcircuits.

Step (A)

First of all, as shown in FIG. 4A, the multilayer body 28 is arranged onone face (upper face) of the wiring circuit substrate 33. At this time,a face on which the protrusions 25 and the interlayer-insulating layer27 of the multilayer body 28 are formed is arranged so as to oppose theaforementioned one face (upper face).

Similarly, the multilayer body 28 is arranged on the other face (lowerface) of the wiring circuit substrate 33. At this time, a face on whichthe protrusions 25 and the interlayer-insulating layer 27 of themultilayer body 28 are formed is arranged so as to oppose theaforementioned other face (lower face).

In this way, a positioning step is performed for the two multilayerbodies 28, that is, the upper and lower multilayer bodies 28.

After the positioning step is carried out, the layers are thermallypress-bonded using an overlaying press, and are thereby integrated intoone unit.

Step (B)

Subsequently, as shown in FIG. 4B, a plurality of resist films 24 isselectively formed on the metal layer 23 of the upper multilayer body28. Similarly, the resist films 24 are selectively formed on the metallayer 23 of the lower multilayer body 28.

Step (C)

Etching is performed for a metal layer 23 of the upper multilayer body28 using the resist films 24 as masks, thereby forming upper conductorcircuits 35. Similarly, etching is performed for a metal layer 23 of thelower multilayer body 28 using the resist films 24 as masks, therebyforming lower conductor circuits 35.

According to the above, a multilayer wiring circuit substrate 36 of thethird embodiment is produced.

The wiring circuit substrate 36 includes the aforementioned wiringcircuit substrate 33 and the upper and lower multilayer bodies 28.

According to the third embodiment, the wiring circuit substrate 36having a plurality of layers of the conductor circuits, for example,four layers of the conductor circuits, can be obtained. This allows thewiring circuit substrate 36 to be of even higher density.

Fourth Embodiment

Hereinbelow, a description will be given of a fourth embodimentaccording to the present invention with reference to FIGS. 5A to 5G and6A and 6B. The fourth embodiment includes configurations that aresubstantially common to those in the first embodiment. FIGS. 5A to 5Gand 6A and 6B are cross-sectional views showing a manufacturing methodfor a wiring circuit substrate according to the fourth embodiment of thepresent invention in the order of manufacturing steps.

Step (A)

The same base member 20 as that shown in FIG. 1A is first prepared.Thereafter, resist films 24 are coated on a surface of a copper foil 21on which protrusions 25 will be formed in a later step. Then, as shownin FIG. 5A, patterning is performed in ways of exposure and development.In particular, patterning is performed for the resist films 24 so thatonly portions where the protrusions 25 will be formed are open and theresist films 24 cover portions where the protrusions 25 will not beformed.

Step (B)

Subsequently, as shown in FIG. 5B, solder-plated layers 37 (each havinga thickness, for example, ranging from 19 μm to 21 μm) are formedaccording to an electric plating method by using the resist films 24 asmasks.

The solder-plated layers 37 are composed of materials, for example, suchas either tin (Sn)/lead (Pb) or tin (Sn)/silver (Ag)/copper (Cu).Alternatively, for the solder-plated layers 37, plated layers of, gold(Au), silver (Ag), or palladium (Pd), may be formed.

Step (C)

Subsequently, step (C) removes the resist films 24, as shown in FIG. 5C.

Step (D)

Subsequently, as shown in FIG. 5D, selective etching is performed forthe metal layer 21 (for example, a copper layer) by using thesolder-plated layers 37 as masks. Thereby, the protrusions 25 areformed.

Step (E)

Subsequently, as shown in FIG. 5E, an etching-barrier layer 22 (forexample, a nickel layer) is removed.

Step (F)

Subsequently, as shown in FIG. 5F, step (F) performs solder-reflowprocessing. In this step, the individual solder-plated layers 37 areoverlaid to cover the surfaces of the individual protrusions 25.

Step (G)

Subsequently, as shown in FIG. 5G, using a heating roller, an insulatingsheet is press-bonded on the surface where the protrusions 25 areformed. Thereby, an interlayer-insulating layer 27 made of theinsulating sheet is formed. In this case, the top (upper portion) ofeach of the protrusions 25 protrudes from the surface of theinterlayer-insulating layer 27. For this reason, theinterlayer-insulating layer 27 is formed so as to have a thicknesssmaller than the combined thicknesses of the J protrusion 25 and thesolder-plated layer 36. Thus, in step (G), a multilayer body 28 isformed.

Step (H)

Subsequently, as shown in FIG. 6A, in step (H), a silver foil 28 iscoated on the entire face of the multilayer body 28. The silver foil 29is, for example, a metal layer for forming conductor circuits, and ispreferably formed so as to have a thickness ranging, for example, from17 μm to 19 μm.

Step (I)

Then, the layers are thermally press-bonded using an overlaying press.Thereafter, resist films are selectively formed on the silver foil 29and the metal layer 23. Then, etching is carried out for the individualsilver foil 29 and metal layer 23 by using the resist films as masks,thereby forming conductor circuits 31 and 32. According to theprocessing described above, the wiring circuit substrate 33 a of thefourth embodiment is produced.

In the described first embodiment, the resist films 24 are used as maskswhen etching is selectively performed for the copper foil 21 and theprotrusions 25 are thereby formed. In the fourth embodiment, however,the solder-plated layers 36 are instead used.

In addition, the solder-plated layers 36 are not removed and are allowedto remain; and before the interlayer-insulating layer 27 made of theinsulating sheet is formed, the condition is arranged such that theprotrusions 25 are covered by the solder-plated layers 36 according tothe solder-reflow processing.

Accordingly, the fourth embodiment does not require application of theconductive paste 26 onto the top (upper portion) of each of theprotrusions 25, while the application is required in the firstembodiment.

Fifth Embodiment

Hereinbelow, a description will be given of a fifth embodiment accordingto the present invention with reference to FIGS. 7A to 7H and 8A to 8C.The fifth embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment.

FIGS. 7A to 7H and 8A to 8C are cross-sectional views showing amanufacturing method for a wiring circuit substrate according to thefifth embodiment in the order of manufacturing steps.

Step (A)

First of all, a base metal 21 a is first prepared. The base metal 21 ais preferably formed of a copper material, for example. Also, the basemetal 21 a is used to form protrusions. The copper foil 21 is preferablyformed to have a thickness, for example, ranging from 0 to 150 μm. Onone face of the base metal 21 a, a photosensitive resin film 40 iscoated, as shown in FIG. 7A.

Step (B)

Subsequently, as shown in FIG. 7B, openings 41 are formed in thephotosensitive resin film 40. The openings 41 are formed so as to opposethe position where protrusions 25 will be formed at a later step.

Step (C)

Subsequently, as shown in FIG. 7C, a wiring film 42 is formed on thesurface of the base metal 21 a where the photosensitive resin film 40 isformed. The wiring film 42 is preferably formed of, for example, acopper material. An example forming procedure for the wiring film 42 isdescribed below.

First, for example, a thin conductive layer made of a Ni-P material isformed according to an electroless plating method. On the surface of theconductive layer, a resist film having a pattern negative to a wiringfilm 42 that will be formed is formed. Using the resist film as a mask,for example, copper-electrolytic plating is performed, and the wiringfilm 42 is thereby formed. Thereafter, the wiring film 42 is used as amask, and the conductive layer is removed to prevent short-circuitingbetween the wiring films 42.

Step (D)

Subsequently, a photosensitive resin film 43 is coated on the surface ofthe base metal 21 a where the wiring film 42 is formed. Thereafter, thephotosensitive resin film 43 is subjected to exposure and development.Thereby, openings 44 for forming terminals are formed. FIG. 7D shows astate where the openings 44 are formed.

Step (E)

Subsequently, as shown in FIG. 7E, protrusion-like microballs 45 areformed on the openings 44 according to, for example, an electrolyticplating method.

Step (F)

Subsequently, as shown in FIG. 7F, the protrusions 25 are formed in thesame method as in the individual embodiments described above.

Step (G)

Subsequently, as shown in FIG. 7G, conductive paste 26 is applied on thetop of each of the protrusions 25 in the same method as in the describedfirst embodiment.

Step (H)

Subsequently, as shown in FIG. 7H, an interlayer insulating layer 27made of an insulating sheet is formed in the same method as in thedescribed first embodiment. The wiring substrate after theinterlayer-insulating layer 27 is formed is assumed to be a substrate 46for the description purpose.

Step (I)

Subsequently, a plurality, for example, two of the substrates 46 isprepared, each having been produced according to steps (H). Also, thewiring circuit substrate 33 of the first embodiment is prepared.

Then, as shown in FIG. 8A, the upper substrate 46 is positioned on theside of one face of the wiring circuit substrate 33. The one face (upperface) of the wiring circuit substrate 33 and a face of the substrate 46on which the protrusions 25 and the interlayer-insulating layer 27 areformed are arranged so as to oppose each other.

On the other hand, the lower substrate 46 is positioned on the side ofthe other face of the wiring circuit substrate 33. The other face (lowerface) of the wiring circuit substrate 33 and a face of the substrate 46on which the protrusions 25 and the interlayer-insulating layer 27 areformed are arranged so as to oppose each other. In this way, apositioning step in the fifth embodiment is performed.

Step (J)

The wiring circuit substrate 33 and the upper and lower substrates 46sandwiching the wiring circuit substrate 33 are pressure-bondedtogether. Thereby, as shown in FIG. 8B, a wiring circuit substrate 47 isformed.

Step (K)

Then, as shown in FIG. 8C, a plurality of LSI chips 48 is mounted on oneface of the wiring circuit substrate 47. Similarly, a plurality of LSIchips 48 is mounted on the other face of the wiring circuit substrate47. In this case, the microballs 45 function as connecting means forconnecting conductor circuits on the wiring circuit substrate 47 and theLSI chips 48.

According to the described wiring circuit substrate 47, the LSI chips 48having a very high integration density can be mounted.

For the embodiment in FIG. 8, various modified examples may be made.First, the described embodiment uses the wiring circuit substrates 46that have a single layer of conductor circuits on the face where theprotrusions 25 are not formed; however, the number of layers of theconductor circuits formed the wiring circuit substrates is notrestricted to be single, and it may be two or more. The layers to beincreased can be easily formed by performing a series of required steps.They are, for example, a step of selectively forming a photosensitiveinsulating resin layer, a step of a thin conductive layer according toan electroless plating method, a step of forming a resist film having apattern negative to a formed pattern, a step of forming conductorcircuits according to an electrolytic plating method by using theconductive layer as a base and using the resist films as masks, and astep of removing the conductive layer by using the conductor circuits asmasks.

Second, in the described present embodiment, the wiring circuitsubstrates 46 are formed so as to be an integral unit via the wiringcircuit substrate 33; however, the configuration is not restrictedthereto and may be modified. For example, the wiring circuit substrates46 may be directly coupled to each other so as to be an integral unit.Alternatively, a configuration may be such that the wiring circuitsubstrates 46 are overlaid via not only the single wiring circuitsubstrate, but also a plurality of the wiring circuit substrates.Furthermore, the members to be mounted on the wiring circuit substrateare not restricted to the bare LSI chips 48, and packaged LSI chips mayinstead be mounted thereon.

Sixth Embodiment

Hereinbelow, a description will be given of a sixth embodiment accordingto the present invention with reference to FIGS. 9A to 9E. The sixthembodiment includes configurations and processing steps that aresubstantially common to those in the first embodiment. FIGS. 9A to 9Eare cross-sectional views showing a manufacturing method for a wiringcircuit substrate according to the sixth embodiment in the order ofmanufacturing steps.

Step (A)

First of all, as shown in FIG. 9A, a base member 51 prepared. The basemember 51 is in a single-layer structure and is made of, for example, ametal plate such as a copper plate. On one face of the base member 51,resist films 52 are selectively formed.

Step (B)

Subsequently, as shown in FIG. 9B, half-etching is performed for thebase member 51 by using resist films 52 as masks. By performinghalf-etching from the surface of the base member 52, protrusions 53 areformed, which work for connecting upper and lower conductors to eachother. The half-etching refers to etching for the surface excludingportions that will be used as circuit-layer portions; it does not referto etching to be performed up to half the thickness of the base member52. In other words, the half-etching refers to etching to be performedfor partial areas.

Step (C)

Subsequently, as shown in FIG. 9C, in step (C), a metal film 54 isappropriately coated on the top of each of protrusions 53. The metalfilm 54 improves connection characteristics and reliability thereof. Themetal film 54 is preferably formed of, for example, conductive paste,solder, a noble metal such as gold, or an anisotropic conductive film.Forming the metal film 54 allows connection characteristics andreliability to be improved; however, the metal film 54 is not mandatory.

Step (D)

Subsequently, as shown in FIG. 9D, a metal foil 56 made of, for example,a copper material, is overlaid on one face of the base member 51 via aninterlayer-insulating layer 55.

Step (E)

Subsequently, as shown in FIG. 9E, etching is selectively performed forthe other face of the base member 51 and the face of the metal foil 56,thereby forming conductor circuits of the individual two faces. In thisway, a wiring circuit substrate that is substantially the same as thatin FIG. 1K is produced. Therefore, the wiring circuit substrate may beused by making modifications as the wiring circuit substrate 36 of theembodiment shown in FIG. 4C, the wiring circuit substrate 47 shown inFIG. 8B, or the wiring circuit substrates 33, or the like.

That is, for portions where the wiring circuit substrate 33 is used, thewiring circuit substrate of the present embodiment is completelymodified thereto, and it can thereby be used.

Also, the wiring circuit substrate in the state before the metal foil 56made of, for example, a copper material, is formed can be used bymodifying it to the wiring circuit substrates 28 shown in FIG. 4, thewiring circuit substrates 46 shown in FIGS. 8A and 8B, or the like.Furthermore, similarly to the wiring circuit substrates 46 shown in FIG.8, the wiring circuit substrate in the state before the metal foil 56 isformed can be used as a multilayer wiring substrate, thereby allowingthe integration density to be increased.

In the described manufacturing method for the wiring circuit substrate,a base member in a multilayer structure having an etching-barrier layerneed not be used. In addition, since a step for removing theetching-barrier layer is not required, the manufacturing cost for thewiring circuit substrate can be reduced.

After the protrusions 53 are formed, a tip surface of each of theprotrusions 53 may be formed in a rough pattern so that manyneedle-shaped prickles are formed thereon, thereby allowing improvementin characteristics of connection with the conductor circuits made of themetal foil 56. The rough preparation for the tip can be implementedaccording to processing such as spray etching or CZ processing.Alternatively, a particle-copper plating method can be used for therough preparation.

In addition, electrolytic chromate processing may be performed for theentire copper surface and the protrusions 53 to form an electrolyticchromate film. This improves antioxidation characteristics of theprotrusions 53 and the copper surface, thereby allowing prevention ofdeterioration in quality of the copper surface due to oxidation.

Each of the protrusions 53 for connecting upper and lower conductors ofthe wiring circuit substrate shown in FIG. 9 has the shape of a konide;however, the configuration of the present invention is not restrictedthereto and allows other types.

For example, as shown in FIG. 10A, protrusions 53 a in the shape of adrum may be formed. The protrusions 53 a can be obtained by modificationin etching conditions. Since the top of the protrusion 53 a is wide,soldering and conductive-paste processing can be easily performed. Inaddition, the protrusions 53 a have advantages in that characteristicsof connection to the conductor circuit can be easily improved.

Alternatively, as shown in FIG. 10B, spear-like protrusions 57 may beformed. The spear-like protrusions 57 have a sharp point, therebyimproving characteristics of passing through the interlayer-insulatinglayer 55. Particularly, characteristics of passing through a prepregcontaining glass cloth can be improved.

In addition, it is easily engaged with the conductor circuit, therebyimproving the characteristics of connection to the conductor circuit.

The spear-like protrusions 57 can be formed by performing etching usinga resist mask having the diameter that is smaller than that of theprotrusion that will be formed. Alternatively, konide-like (ordrum-like) protrusions are first formed by performing selective etching(half-etching) with resist films or the like as masks; and thereafter,the masks are removed, then etching (half-etching) is performed again,thereby allowing the spear-like protrusion 57 to be formed.

Seventh Embodiment

Hereinbelow, a description will be given of a seventh embodimentaccording to the present invention with reference to FIG. 11. Theseventh embodiment includes configurations and processing steps that aresubstantially common to those in the first embodiment.

FIG. 11 is a perspective view of a wiring circuit substrate according tothe seventh embodiment. In the configuration shown in FIG. 11,protrusions 53 (or, protrusion 57 or 25; for the protrusions 25, referto FIGS. 1 to 8) the wiring circuit substrate of the seventh embodimentare arranged at cross sections of a matrix.

In the seventh embodiment, the protrusions 53 are arranged at crosssections of a matrix, which is made of vertical and horizontal lines(conceptual lines) given at predetermined spaces therebetween. Theprotrusions to be used in the present embodiment are not restricted tothose with the reference number 53, one of other types of protrusionsthat have different sizes and shapes may be used. The protrusions usedin the described embodiments may be arranged in the wiring circuitsubstrate of the present embodiment.

According to the wiring circuit substrate of the seventh embodiment,conductor circuits having different patterns can be formed depending onthe model of the wiring circuit substrate. In specific, at a stagebefore conductor circuits are formed by performing etching, the wiringcircuit substrate having the matrix-type protrusions are mass-produced.Thereafter, conductor circuits of various patterns can be formeddepending on the model. Thus, only specific protrusions are used forinterlayer connection, and no other protrusions are used. Even in a casewhere unnecessary protrusions have been formed, they can be removed byperforming overetching. The above procedure allows improvement in theproductivity of different models of wiring circuit substrates.

Eighth Embodiment

Hereinbelow, a description will be given of an eighth embodimentaccording to the present invention with reference to FIG. 12. The eighthembodiment includes configurations and processing steps that aresubstantially common to those in the first embodiment.

FIG. 12 is a perspective view of a wiring circuit substrate according tothe eighth embodiment. As shown in the figure, in the presentembodiment, protrusions 53 are formed so that a uniformed pressure isapplied to each of the protrusions 53 in overlaying a metal layer 56 viaan interlayer-insulating layer 55.

According to this embodiment, the uniformity of the pressure on a facethat is applied at the overlaying step can be improved. This improvesthe uniformity in the collapse degree of the protrusions 53. Also, thepresent embodiment improves the uniformity in the board thickness of thewiring circuit substrate, thereby allowing the reliability of the wiringcircuit substrate to be improved.

Ninth Embodiment

Hereinbelow, a description will be given of a ninth embodiment accordingto the present invention with reference to FIG. 13. The ninth embodimentincludes configurations and processing steps that are substantiallycommon to those in the first embodiment.

FIG. 13 is a cross-sectional view of a wiring circuit substrateaccording to the ninth embodiment. As shown in the figure, in thepresent embodiment, the density of arrangement of protrusions 57 thatconnect upper and lower conductors to each other is varied depending onthe place. Specifically, the protrusions 57 are arranged to formnon-dense areas (n areas) and dense areas (m areas). In addition, aroundthe area where the protrusions 57 are arranged at a high density, dummyprotrusions 58 that are lower than the protrusions 57 for connectingupper and lower conductors to each other are arranged. This arrangementallows the uniformity in the diameter and the height to be improved.

More specifically, in the area where the protrusions 57 are formed at ahigh density, flow of etchant after sprayed differs in peripheralportions and central portions. Accordingly, the etching rate differs inthe peripheral portions and the central portions. The etching rate ishigher in the peripheral portions of the protrusions where the etchantflows faster than in the central portions. Therefore, the diameter ofthe protrusion in the peripheral portions tends to be small, and theheight thereof also tends to be small.

In view of the above, the ninth embodiment is configured such that theperipheral areas are surrounded by the dummy protrusions 58 that have nodirect influence on the circuits (do not configure the circuits). Thisconfiguration allows the etching rate to be low for the peripheralprotrusions 57 that connect upper and lower conductors to each other.Therefore, even the peripheral protrusions 57 can be made to have thesame diameter and height as those of the central protrusions 57.

In addition, it is preferable that the dummy protrusions 58 be formed tohave a smaller diameter of a resist portion used for masking than thatof other protrusions 57 so that they disappear after etching.

Tenth Embodiment

Hereinbelow, a description will be given of a tenth embodiment accordingto the present invention with reference to FIGS. 14A to 14D. The tenthembodiment includes configurations and processing steps that aresubstantially common to those in the first embodiment. FIGS. 14A to 14Dare plan views individually showing configurations of protrusions ofwiring circuit substrates according to the tenth embodiment.

In the above-described ninth embodiment, in a case where the spacebetween the individual protrusions that connect upper and lowerconductors to each other is large, the etching rare differs in theperipheral portions and the central portions of the protrusion. In thiscase, adverse effects are caused due to the difference. In view of theproblem, in the tenth embodiment, the dummy protrusions 58 are arrangedaround the protrusions 57 that connect upper and lower conductors toeach other.

In a protrusion 57 in FIG. 14A, dummy protrusions 58 formed as a ringare formed around each of the protrusions 57 that connect upper andlower conductors to each other. In this case, at least, each couple ofthe adjacent dummy protrusions 58 is formed at a spacing from eachother.

In a protrusion 57 in FIG. 14B, in which ring-like dummy protrusions arearranged are formed similar to the above, but the adjacent dummyprotrusions 58 are formed so as to partially overlap with each other.

In a protrusion 57C in FIG. 14C, a plurality of ring-like dummyprotrusions 58 is formed around each of the protrusions 57 that connectupper and lower conductors to each other. In this case, the plurality ofdummy protrusions 58 is formed only on a circular line around each ofthe protrusions 57.

In a protrusion 57D in FIG. 14D, dummy protrusions 58 are formedvertically and horizontally at a predetermined spacing therebetween inthe outside area of a circular line 58 a around each of the protrusions57.

Eleventh Embodiment

Hereinbelow, a description will be given of an eleventh embodimentaccording to the present invention with reference to FIG. 15. Theeleventh embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment. FIG. 15 is across-sectional view of a wiring circuit substrate according to theeleventh embodiment.

As shown in FIG. 15, in the wiring circuit substrate of the eleventhembodiment, protrusions 53 for connecting upper and lower conductors toeach other are formed including protrusions 53 h and 531 that havedifferent heights. These protrusions 53 h and 531, which have differentheights, are included to connect the protrusions 53, which connect upperand lower conductors to each other, to stepped connection faces.

In FIG. 15, a core substrate 60 having stepped connection faces isformed. On two faces of the core substrate 60, wiring circuit substratesusing the protrusions 53 as means for connecting upper and lowerconductors to each other are overlaid. In this case, the high protrusion53 h is connected to the copper paste 100, and the low protrusion 531 isconnected to the copper wiring section 54.

The protrusion 53 h and the low protrusion 531, which have differentheights, are preferably formed as follows. First of all, mask portionsof masks made of resist films used in etching are formed to havedifferent diameters. Then, using the surface of the base member, etchingis performed. In specific, a mask portion for covering a portion wherethe high protrusion 53 h will be formed is formed to have a largediameter. On the other hand, a mask portion for masking a portion wherethe low protrusion 53 b will be formed is formed to have a smalldiameter. The above-described protrusions are thereby formed.

In the wiring circuit substrates shown in FIG. 15, a metal layer (film)is not formed on the copper wiring film 54 of the core substrate 60. Themetal layer is supposed to be formed of conductive paste, solder, anoble metal, or the like.

However, the protrusion 53 (57) made of a copper material is directlyformed on the copper wiring film 54. Even in this example, the presentinvention can be effective. This is also applicable either to aconfiguration having high protrusions 53 a and low protrusions 53 b orto a configuration having the protrusions 53 (57) that have uniformedheights.

In the configuration in which the each of the copper protrusions 53 (57)is directly connected to each of the copper wiring films 54 without anoble metal layer (film) made of solder, a noble metal, or the likebeing provided therebetween, as shown by broken lines in FIG. 15,openings 54 a each having a diameter smaller than that of the top ofeach of the protrusions 53 (57) may be formed on the individual copperwiring films 54. The configuration is arranged so that, when theprotrusion 53 (57) is connected to the copper wiring film 54, the top ofthe protrusion 53 (57) abuts the opening 54 a and collapses it, therebyallowing the strength of the connection between the protrusion 53 (57)and the metal film 54 to be increased. Of course, forming of theopenings 54 a is significantly effective in any of the describedconfigurations, that is, either in the configuration having theprotrusions 53 h and 531 that have different heights, as shown in FIG.15, or in the configuration having the protrusions 53 that haveuniformed heights.

Twelfth Embodiment

Hereinbelow, a description will be given of a twelfth embodimentaccording to the present invention with reference to FIGS. 16A and 16B.The twelfth embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment.

FIG. 16A is a perspective view of a wiring circuit substrate accordingto the twelfth embodiment, and FIG. 16B is a cross-sectional viewthereof.

FIG. 16A (perspective view) and 16B (cross-sectional view) show majorportions of the wiring circuit substrate of the present embodiment in astate before conductor circuits are formed. The wiring circuit substrateis arranged such that protrusions for connecting upper and lowerconductors to each other are formed; spacers 61 are formed of the samematerial as that for, for example, the protrusions 57, to have the sameheight as that of the protrusions in the same step at which theprotrusions are formed; and also, a predetermined spacing betweenconductor circuits formed of a copper base member 51 on the wiringcircuit substrate and a core substrate (not shown in FIG. 16) ismaintained, and the thickness of an insulating layer is set to apredetermined position; thereby improving impedance-controllability.

Specifically, the protrusions are formed by performing selective etchingfor the base member 51, and the protrusions thus formed are used forconnecting upper and lower conductors to each other. However, generally,an insulating sheet does not have a good characteristic in regard to thethickness tolerance, and also, the finished thickness thereof variesaccording to temperature and pressure applied at an overlaying step,thereby making it difficult to obtain a uniform thickness of theinsulating sheet. Therefore, the spacing between the copper foiloverlaid on the insulating sheet and the core substrate is not constant,thereby making impedance control of the wiring circuit substrate to bedifficult.

In view of the above problems, the present embodiment is arranged suchthat the spacers 61 are formed in appropriate portions, and theindividual spacers 61 are pressed until they abut the core substratethrough a prepreg so as to push out an excessive insulating material toperipheral portions, thereby making the spacing between upper and lowercopper patterns to be constant to allow the impedance-controllability tobe improved. The spacers 61 may be formed in any pattern, for example,in a matrix or in a frame, unless they become obstacles to forming ofthe conductor circuits. The spacers 61 can also be used as ground linesfor electrostatic shields.

Thirteenth Embodiment

Hereinbelow, a description will be given of a thirteenth embodimentaccording to the present invention with reference to FIG. 17. Thethirteenth embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment. FIG. 17 is across-sectional view showing a protrusion of a wiring circuit substrateaccording to the thirteenth embodiment.

As shown in FIG. 17, the wiring circuit substrate of the thirteenthembodiment is configured including large-diameter protrusions 53 x andsmall-diameter protrusions 53 y. A high current is applied to flow inthe large-diameter protrusions 53 x that connect upper and lowerconductors to each other. On the other hand, a low current is applied toflow in the small-diameter protrusions 53 y that connect upper and lowerconductors to each other.

According to the embodiment described above, either a high current or alow current can be applied to the uniformly small protrusions thatconnect upper and lower conductors to each other. This prevents anon-negligible voltage drop and heat generation in thehigh-current-passing protrusions that connect upper and lower conductorsto each other. In addition, either a low current or a high current canbe applied to flow in the relatively large protrusions (in the uniformsize) that connect upper and lower conductors to each other. Thisarrangement solves a problem possibly arising in that thelow-current-passing protrusions exclusively use an unnecessary largearea to be an obstacle to improvement in integration density.

Fourteenth Embodiment

Hereinbelow, a description will be given of a fourteenth embodimentaccording to the present invention with reference to FIGS. 18A to 18C.The fourteenth embodiment includes configurations and processing stepsthat are substantially common to those in the first embodiment.

FIG. 18A is a perspective view showing a configuration of a wiringcircuit substrate according to the fourteenth embodiment.

As shown in FIG. 18A, in the same step in which protrusions 53 (57) areformed, alignment marks or identification marks 63 for identification ofmodels or the like are formed.

FIG. 18A shows a stage before a copper foil or the like is formed via aninterlayer-insulating layer on the side where the protrusions areformed.

FIG. 18B shows an identification mark 63 a (alignment mark pattern) asan example of the identification mark 63. Also, FIG. 18C shows anotherexample identification mark 63 b (alignment mark pattern).

In the present embodiment, since the identification marks 63 are formedin the same step at which the protrusions 53 (57) are formed, theidentification marks 63 are formed of the same material as that for theprotrusions 53 (57) to have the same height as that thereof.

According to the present embodiment described above, since the marks 63are formed in the same step at which the protrusions 53 (57) are formed,there is an advantage in that a step dedicated to forming the marks 63is not required. In addition, since the marks 63 are formed in the samestep at which the protrusions 53 (57) are formed, the positionaldeviation between the marks 63 and the individual protrusions can beminimized.

Fifteenth Embodiment

Hereinbelow, a description will be given of a fifteenth embodimentaccording to the present invention with reference to FIGS. 19A to 19D.The fifteenth embodiment includes configurations and processing stepsthat are substantially common to those in the first embodiment. FIGS.19A to 19D are cross-sectional views showing a manufacturing method fora wiring circuit substrate according to the fifteenth embodiment in theorder of manufacturing steps.

Step (A)

First of all, as shown in FIG. 19A, a core substrate 70 is prepared. Thecore substrate 70 is configured including at least one insulatingsubstrate 71, a plurality of conductor circuits 72 formed on two facesof the core substrate 70, and through-holes 73 formed in the insulatingsubstrate 71. Peripheral portions of the through-holes 73 are covered bythe conductor circuits 72; that is, the conductor circuit 72 is alsoformed between the through-hole 73 and the insulating substrate 71.

The insulating substrate 71 is preferably formed of, for example, resin.The conductor circuits 72 are preferably formed of, for example, acopper material. The through-hole 73 functions for connecting conductorsformed on one face of the insulating substrate 71 and conductors formedon the other face of the insulating substrate 71.

On the two faces of the core substrate 70 composed as described above,individual wiring circuit substrates including either protrusions 53 orprotrusions 57, which will be described below, are overlaid.

Step (B)

Subsequently, as shown in FIG. 19B, metal layers 74 are formed on theconductor circuits 72 individually corresponding to the protrusions onthe wiring circuit substrates that will be overlaid. The metal layers 74are preferably formed of, for example, conductive paste, solder, and anoble metal.

Step (C)

Subsequently, as shown in FIG. 19C, wiring circuit substrates 75 areindividually overlaid on two faces of the core substrate 70. Individualprotrusions 53 are connected to the metal layers 74 at positionscorresponding to the metal layers 74. The protrusions 53 are formed byextending base members 51. An interlayer-insulating layer 55 is formedbetween one face of the insulating substrate 71 and the base member 51of one of the wiring circuit substrates 75. Also, aninterlayer-insulating layer 55 is formed between the other face of theinsulating substrate 71 and the base member 51 of the other one of thewiring circuit substrates 75.

Step (D)

Subsequently, as shown in FIG. 19D, etching is selectively performed forthe individual base members 51 on the two faces of the wiring circuitsubstrates 75. Thereby, patterning is performed to form the conductorcircuits. Thus, by arranging the configuration made according to the atleast two wiring circuit substrates 75 and the core substrate 70, highcircuit integration can be implemented. Furthermore, the reliability ofconnection between the individual protrusions and the individualconductor circuits is improved, therefore allowing the wiring circuitsubstrate to be manufactured to have high quality.

The etching step for the base members 51 may be performed prior to thestep of overlaying the wiring circuit substrates 75 on the two faces ofthe core substrate 20.

Sixteenth Embodiment

Hereinbelow, a description will be given of a sixteenth embodimentaccording to the present invention with reference to FIGS. 20A to 20C.The sixteenth embodiment includes configurations and processing stepsthat are substantially common to those in the first embodiment.

The present embodiment is configured such that, in the describedfifteenth embodiment, openings 72 a having the diameter larger than thatof the top of each of the protrusions 53 are formed in the individualconductor circuits 72 to which the protrusions 53 are connected.

FIG. 20A is a cross-sectional view of the embodiment described above.FIG. 20B is a plan view of a configuration of one of the conductorcircuits 72 connected to the protrusions 53.

In the present embodiment, as shown in FIG. 20A, the openings 72 a areindividually formed in the conductor circuits 72.

The conductor circuits 72 are formed on the entire face of, for example,the insulating substrate 71 in the core substrate. The openings 72 a areformed in the individual conductor circuits 72 formed on the insulatingsubstrate 71. It is preferable that the openings 72 a be formeddepending on the size, the shape, the arrangement position, the number,and the like of the protrusions in the individual embodiments describedabove. For example, a plurality of the openings 72 a may be formed inone conductor circuit 72. In addition, the diameters of the individualopenings must be larger than the diameter of the protrusions, but may bedifferent from each other. Furthermore, the individual openings are notrestricted to be circular, but may be polygonal.

According to the above, the protrusion 53 can be partially inserted intothe opening 72 a via the metal layer 74. This allows the connectionstrength between the protrusions 53 and the conductor circuits 72 to beincreased. Therefore, the reliability of the connection between thewiring circuit substrates 75 and the core substrate can be furtherimproved.

The metal layers 74 are preferably formed of conductive paste, solder, anoble metal, or the like.

FIG. 20C is a cross-sectional view of a modified example of the presentembodiment. In the figure, first of all, a metal layer 74 is formed onthe surface of a conductor circuit 72 and an opening 72 a.

After the metal layer 74 is formed, part of the metal layer 74 thatprotrudes from the surface of the conductor circuit 72 is removed byperforming polishing. Thereby, the metal layer 74 can be formed only inthe inside of the opening 72 a.

In this case, for example, when the wiring circuit substrates 75 areoverlaid, they are connected to each other in a condition that each ofthe protrusions 53 or 57 is inserted into the conductive paste layer,the solder layer, or the metal layer 74 in each of the openings 72 a.

Seventeenth Embodiment

Hereinbelow, a description will be given of a seventeenth embodimentaccording to the present invention with reference to FIGS. 21A to 21C.The seventeenth embodiment includes configurations and processing stepsthat are substantially common to those in the first embodiment.

FIGS. 21A to 21C are cross-sectional views showing a manufacturingmethod for a wiring circuit substrate according to the tenth embodimentin the order of manufacturing steps.

Step (A)

As shown in FIG. 21A, a silver foil 56 is prepared on one side of awiring circuit substrate that will be connected to protrusions 53 (or,protrusions 57 or the like). A plurality of metal layers 76 is formed inpositions corresponding to the protrusions 53 on a face opposing theprotrusions 53 of the silver foil 56.

Preferably, the metal layers 76 are members, for example, aconductive-paste layer, a solder layer, and a noble metal (such asgold), that are suitable for securing connection characteristics orimproving the connection characteristics.

Step (B)

Subsequently, as shown in FIG. 21B, an interlayer-insulating layer 55 isarranged between the silver foil 56 on which the plurality of metallayers 76 is provided and a base member 51 on which a plurality ofprotrusions 53 is formed.

Step (C)

Subsequently, as shown in FIG. 21C, the silver foil 56 is overlaid onthe base member 51, which has the protrusions 53, via theinterlayer-insulating layer 55. At this time, the protrusions 53 piercethe interlayer-insulating layer 55 and are in contact with the metallayers 76.

Subsequently, although it is not shown in the figures, etching isselectively performed for the base member 51 and the silver foil 56 atthe same time or at different time, thereby forming conductor circuitson the individual upper and lower faces.

According to the embodiment described above, good characteristics of theconnection between the protrusions 53 and the conductor circuits formedof the silver foil 56 can be obtained.

Eighteenth Embodiment

Hereinbelow, a description will be given of an eighteen embodimentaccording to the present invention with reference to FIG. 22. Theeighteenth embodiment includes configurations and processing steps thatare substantially common to those in the first embodiment.

FIG. 22 is a cross-sectional view of a wiring circuit substrate of thepresent embodiment. As shown in FIG. 22, the wiring circuit substrate ofthe present embodiment uses an anisotropic conductive film 55 a as aninterlayer-insulating layer 55.

The anisotropic conductive film 55 a is formed of dispersed metalparticles. According to application of a vertical pressure, conductiveparticles are forced to fill between each of the protrusions 53 and thesilver foil 56. When the conductive particles are pressed, they areinserted into the individual faces, thereby improving the reliability ofconnection. At this time, the portion sandwiched by each of theprotrusions 53 and the interlayer-insulating layer 55 becomesconductive, but other portions retain insulation characteristics.

As described above, characteristics of the connection between theprotrusions 53 and the silver foil 56 are secured according to theanisotropic conductive film 55 a, and in addition, the insulationcharacteristics required for the interlayer-insulating layer can besecured.

In the above, the anisotropic conductive film may be formed only on theprotrusions 53, and the interlayer-insulating layer may be formed of astandard resin material. In these cases, the protrusions 53 and thesilver foil 56 are electrically connected to each other via theanisotropic conductive film, and the insulation is secured via thestandard insulating material.

Nineteenth Embodiment

Hereinbelow, a description will be given of a nineteenth embodimentaccording to the present invention with reference to FIGS. 23A to 23C.The nineteenth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 23A to 23C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 23A to 23C, a multilayer wiring circuit substrate 36Bis formed by overlaying the individual wiring circuit substrates 28A(first and third wiring circuit substrates) shown in FIG. 1G in thedescribed first embodiment, and the wiring circuit substrate 33B (secondwiring circuit substrate) shown in FIG. 3F in the described secondembodiment. The wiring circuit substrate 33B (second wiring circuitsubstrate) is overlaid on the wiring circuit substrate 28A (first wiringcircuit substrate), and the wiring circuit substrate 28A (third wiringcircuit substrate) is overlaid on the wiring circuit substrate 33B(second wiring circuit substrate).

To configure the wiring circuit substrate 36B, the two wiring circuitsubstrates 28A are preliminarily manufactured according to amanufacturing method similar to that having steps (A) to (G) in thefirst embodiment. Concurrently, the wiring circuit substrate 33B ispreliminarily manufactured according to a manufacturing method similarto that having steps (A) to (F) in the second embodiment.

Subsequently, as shown in FIG. 23A, positioning is carried out byarranging the upper and lower wiring circuit substrates 28A with thewiring circuit substrate 33B being placed therebetween. Then, they arethermally press-bonded to each other by using an overlaying press so asto be a sandwich-like integral unit.

After the above overlaying step, resist films 24 are selectively formedon the upper surface of the upper wiring circuit substrate 28A and thelower surface of the lower wiring circuit substrate 28A. Subsequently,patterning is performed for the individual wiring circuit substrates 28Aby performing etching therefor using the resist films 24 as masks,thereby forming conductor circuits 35. According to the above procedure,a plurality of conductor circuits is obtained, and the multilayer wiringcircuit substrate 36B is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twentieth Embodiment

Hereinbelow, a description will be given of a twentieth embodimentaccording to the present invention with reference to FIGS. 24A to 24C.The twentieth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 24A to 24C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 24A to 24C, a multilayer wiring circuit substrate 36Cis formed by overlaying the individual wiring circuit substrates 28C(first and third wiring circuit substrates) shown in FIG. 6 in thedescribed fourth embodiment, and the wiring circuit substrate 33B(second wiring circuit substrate) shown in FIG. 3F in the describedsecond embodiment. The wiring circuit substrate 33B (second wiringcircuit substrate) is overlaid on the wiring circuit substrate 28C(first wiring circuit substrate), and the wiring circuit substrate 28C(third wiring circuit substrate) is overlaid on the wiring circuitsubstrate 33B (second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36C, the individual wiring circuit substrates 28C and thewiring circuit substrate 33 b are preliminarily manufactured accordingto manufacturing methods similar to those in the correspondingembodiments. Subsequently, they are thermally press-bonded to each otherby using an overlaying press so as to be a sandwich-like integral unit.After the overlaying step, etching is performed for the upper and lowerwiring circuit substrates of the wiring circuit substrate 36C by usingresist films on the individual upper and lower surface as masks.Thereby, a plurality of conductor circuits is obtained, and themultilayer wiring circuit substrate 36C is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twenty-First Embodiment

Hereinbelow, a description will be given of a twenty-first embodimentaccording to the present invention with reference to FIGS. 25A to 25C.The twenty-first embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 25A to 25C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 25A to 25C, a multilayer wiring circuit substrate 36Dis formed by overlaying the wiring circuit substrate 28A (first wiringcircuit substrate) shown in FIG. 1G in the described first embodiment;the wiring circuit substrate 33B (second wiring circuit substrate) shownin FIG. 3F in the described second embodiment, and the wiring circuitsubstrate 28C (third wiring circuit substrate) shown in FIG. 6 in thedescribed fourth embodiment. The wiring circuit substrate 33B (secondwiring circuit substrate) is overlaid on the wiring circuit substrate28A (first wiring circuit substrate), and the wiring circuit substrate28C (third wiring circuit substrate) is overlaid on the wiring circuitsubstrate 33B (second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36D, the individual wiring circuit substrates 28A, 33B, and28C are preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 36D by using resist films on theindividual upper and lower surface as masks. Thereby, a plurality ofconductor circuits is obtained, and the multilayer wiring circuitsubstrate 36D is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twenty-Second Embodiment

Hereinbelow, a description will be given of a twenty-second embodimentaccording to the present invention with reference to FIGS. 26A to 26C.The twenty-second embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 26A to 26C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 26A to 26C, a multilayer wiring circuit substrate 47Bis formed by overlaying the wiring circuit substrates 46 (first andthird wiring circuit substrates) shown in FIG. 7 in the described fifthembodiment, the wiring circuit substrate 33B (second wiring circuitsubstrate) shown in FIG. 3F in the described second embodiment, and aplurality of LSI chips 48. The wiring circuit substrate 33B (secondwiring circuit substrate) is overlaid on the wiring circuit substrate 46(first wiring circuit substrate), the wiring circuit substrate 46 (thirdwiring circuit substrate) is overlaid on the wiring circuit substrate33B (second wiring circuit substrate), and in addition, the plurality ofLSI chips 48 is overlaid outside of the wiring circuit substrates 46(first and third wiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47B, the individual wiring circuit substrates 46 and thewiring circuit substrate 33B are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 47B by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47B is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Twenty-Third Embodiment

Hereinbelow, a description will be given of a twenty-third embodimentaccording to the present invention with reference to FIGS. 27A to 27C.The twenty-third embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 27A to 27C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment,

As shown in FIGS. 27A to 27C, a multilayer wiring circuit substrate 47Cis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 33B (second wiring circuit substrate) shownin FIG. 3F in the described second embodiment, the wiring circuitsubstrate 28A (third wiring circuit substrate) shown in FIG. 1G in thedescribed first embodiment, and a plurality of LSI chips 48. The wiringcircuit substrate 33B (second wiring circuit substrate) is overlaid onthe wiring circuit substrate 46 (first wiring circuit substrate), thewiring circuit substrate 28A (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33B (second wiring circuitsubstrate), and in addition, the plurality of LSI chips 48 is overlaidoutside of the wiring circuit substrates 28A and 46 (third and firstwiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47C, the individual wiring circuit substrates 46, 33B, and 28Aare preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47C by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47C is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Twenty-Fourth Embodiment

Hereinbelow, a description will be given of a twenty-fourth embodimentaccording to the present invention with reference to FIG. 28. Thetwenty-fourth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIG. 28 is a cross-sectionalview showing a multilayer wiring circuit substrate of the presentembodiment.

As shown in FIG. 28, a multilayer wiring circuit substrate 36E is formedby overlaying the wiring circuit substrates 28C (first and third wiringcircuit substrates) shown in FIG. 6 in the described fourth embodiment,and the wiring circuit substrate 33C (second wiring circuit substrate)shown in FIG. 6 in the same fourth embodiment. The wiring circuitsubstrate 33C (second wiring circuit substrate) is overlaid on thewiring circuit substrate 28C (first wiring circuit substrate), and thewiring circuit substrate 28C (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33C (second wiring circuitsubstrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36E, the individual wiring circuit substrates 28C and thewiring circuit substrate 33C are preliminarily manufactured according toa manufacturing method similar to that in the corresponding embodiment.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 36E by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained, and in addition, themultilayer wiring circuit substrate 36E is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twenty-Fifth Embodiment

Hereinbelow, a description will be given of a twenty-fifth embodimentaccording to the present invention with reference to FIGS. 29A to 29C.The twenty-fifth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 29A to 29C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 29A to 29C, a multilayer wiring circuit substrate 36Fis formed by overlaying the wiring circuit substrates 28A (first andthird wiring circuit substrates) shown in FIG. 1G in the described firstembodiment, and the wiring circuit substrate 33C (second wiring circuitsubstrate) shown in FIG. 6 in the fourth embodiment. The wiring circuitsubstrate 33C (second wiring circuit substrate) is overlaid on thewiring circuit substrate 28A (first wiring circuit substrate), and thewiring circuit substrate 28A (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33C (second wiring circuitsubstrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36F, the individual wiring circuit substrates 28A and thewiring circuit substrate 33C are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 36F by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained, and in addition, themultilayer wiring circuit substrate 36F is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twenty-Sixth Embodiment

Hereinbelow, a description will be given of a twenty-sixth embodimentaccording to the present invention with reference to FIGS. 30A to 30C.The twenty-sixth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 30A to 30C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 30A to 30C, a multilayer wiring circuit substrate 36Gis formed by overlaying the wiring circuit substrate 28A (first wiringcircuit substrate) shown in FIG. 1G in the described first embodiment;the wiring circuit substrate 33C (second wiring circuit substrate) shownin FIG. 6 in the described fourth embodiment, and the wiring circuitsubstrate 28C (third wiring circuit substrate) shown in FIG. 6 in thedescribed fourth embodiment. The wiring circuit substrate 33C (secondwiring circuit substrate) is overlaid on the wiring circuit substrate28A (first wiring circuit substrate), and the wiring circuit substrate28C (third wiring circuit substrate) is overlaid on the wiring circuitsubstrate 33C (second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36G, the individual wiring circuit substrates 28A, 33C, and28C are preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 36G by using resist films on theindividual upper and lower surface as masks. Thereby, a plurality ofconductor circuits is obtained, and the multilayer wiring circuitsubstrate 36G is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Twenty-Seventh Embodiment

Hereinbelow, a description will be given of a twenty-seventh embodimentaccording to the present invention with reference to FIGS. 31A to 31C.The twenty-seventh embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 31A to 31C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 31A to 31C, a multilayer wiring circuit substrate 47Dis formed by overlaying the wiring circuit substrates 46 (first andthird wiring circuit substrates) shown in FIG. 7 in the described fifthembodiment, the wiring circuit substrate 33C (second wiring circuitsubstrate) shown in FIG. 6 in the described fourth embodiment, and aplurality of LSI chips 48. The wiring circuit substrate 33C (secondwiring circuit substrate) is overlaid on the wiring circuit substrate 46(first wiring circuit substrate), the wiring circuit substrate 46 (thirdwiring circuit substrate) is overlaid on the wiring circuit substrate33C (second wiring circuit substrate), and in addition, the plurality ofLSI chips 48 is overlaid outside of the wiring circuit substrates 46(first and third wiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47D, the individual wiring circuit substrates 46 and thewiring circuit substrate 33C are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 47D by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47D is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Twenty-Eighth Embodiment

Hereinbelow, a description will be given of a twenty-eighth embodimentaccording to the present invention with reference to FIGS. 32A to 32C.The twenty-eighth embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 32A to 32C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 32A to 32C, a multilayer wiring circuit substrate 47Eis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 33C (second wiring circuit substrate) shownin FIG. 6B in the described fourth embodiment, the wiring circuitsubstrate 28A (third wiring circuit substrate) shown in FIG. 1G in thedescribed first embodiment, and a plurality of LSI chips 48. The wiringcircuit substrate 33C (second wiring circuit substrate) is overlaid onthe wiring circuit substrate 46 (first wiring circuit substrate), thewiring circuit substrate 28A (third wiring circuit substrate) isoverlaid on'the wiring circuit substrate 33C (second wiring circuitsubstrate), and in addition, the plurality of LSI chips 48 is overlaidoutside of the wiring circuit substrates 28A and 46 (third and firstwiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47E, the individual wiring circuit substrates 46, 33C, and 28Aare preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47E by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47E is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Twenty-Ninth Embodiment

Hereinbelow, a description will be given of a twenty-ninth embodimentaccording to the present invention with reference to FIGS. 33A to 33C.The twenty-ninth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 33A to 33C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 33A to 33C, a multilayer wiring circuit substrate 47Fis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 33C (second wiring circuit substrate) shownin FIG. 6 in the described fourth embodiment, the wiring circuitsubstrate 28C (third wiring circuit substrate) shown in FIG. 6 in thedescribed fourth embodiment, and a plurality of LSI chips 48. The wiringcircuit substrate 33C (second wiring circuit substrate) is overlaid onthe wiring circuit substrate 46 (first wiring circuit substrate), thewiring circuit substrate 28C (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33C (second wiring circuitsubstrate), and in addition, the plurality of LSI chips 48 is overlaidoutside of the wiring circuit substrates 28C and 46 (third and firstwiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47F, the individual wiring circuit substrates 46, 33C, and 28Care preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47F by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47F is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirtieth Embodiment

Hereinbelow, a description will be given of a thirtieth embodimentaccording to the present invention with reference to FIG. 34. Thethirtieth embodiment includes configurations and processing steps thatare substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIG. 34 is a cross-sectionalview showing a multilayer wiring circuit substrate of the presentembodiment.

As shown in FIG. 34, a multilayer wiring circuit substrate 36H is formedby overlaying the wiring circuit substrates 28C (first and third wiringcircuit substrates) shown in FIG. 5A (FIG. 6) in the described fourthembodiment, and the wiring circuit substrate 33A (second wiring circuitsubstrate) shown in FIG. 2D (FIG. 2) in the described first embodiment.The wiring circuit substrate 33A (second wiring circuit substrate) isoverlaid on the wiring circuit substrate 28C (first wiring circuitsubstrate), and the wiring circuit substrate 28C (third wiring circuitsubstrate) is overlaid on the wiring circuit substrate 33A (secondwiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36H, the individual wiring circuit substrates 28C and thewiring circuit substrate 33A are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 36H by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained, and in addition, themultilayer wiring circuit substrate 36H is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Thirty-First Embodiment

Hereinbelow, a description will be given of a thirty-first embodimentaccording to the present invention with reference to FIGS. 35A to 35C.The thirty-first embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 35A to 35C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 35A to 35C, a multilayer wiring circuit substrate 36Iis formed by overlaying the wiring circuit substrate 28A (first wiringcircuit substrate) shown in FIG. 1G in the described first embodiment,the wiring circuit substrate 33B (second wiring circuit substrate) shownin FIG. 1 in the first embodiment, and the wiring circuit substrate 28C(third wiring circuit substrate) shown in FIG. 6 in the fourthembodiment. The wiring circuit substrate 33B (second wiring circuitsubstrate) is overlaid on the wiring circuit substrate 28A (first wiringcircuit substrate), and the wiring circuit substrate 28C (third wiringcircuit substrate) is overlaid on the wiring circuit substrate 33B(second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36I, the individual wiring circuit substrates 28A, 33B, and28C are preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 36I by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained, and in addition, the multilayer wiringcircuit substrate 36I is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Thirty-Second Embodiment

Hereinbelow, a description will be given of a thirty-second embodimentaccording to the present invention with reference to FIGS. 36A to 36C.The thirty-second embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 36A to 36C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 36A to 36C, a multilayer wiring circuit substrate 47Gis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 33A (second wiring circuit substrate) shownin FIG. 1 in the described first embodiment, the wiring circuitsubstrate 28C (third wiring circuit substrate) shown in FIG. 6 in thedescribed fourth embodiment, and a plurality of LSI chips 48. The wiringcircuit substrate 33A (second wiring circuit substrate) is overlaid onthe wiring circuit substrate 46 (first wiring circuit substrate), thewiring circuit substrate 28C (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33A (second wiring circuitsubstrate), and in addition, the plurality of LSI chips 48 is overlaidoutside of the wiring circuit substrates 46 and 28C (first and thirdwiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47G, the individual wiring circuit substrates 46, 33A, and 28Care preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47G by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47G is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirty-Third Embodiment

Hereinbelow, a description will be given of a thirty-third embodimentaccording to the present invention with reference to FIGS. 37A to 37C.The thirty-third embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 37A to 37C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 37A to 37C, a multilayer wiring circuit substrate 47His formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 33A (second wiring circuit substrate) shownin FIG. 1G in the described first embodiment, the wiring circuitsubstrate 28A (third wiring circuit substrate) shown in FIG. 1G in thedescribed first embodiment, and a plurality of LSI chips 48. The wiringcircuit substrate 33A (second wiring circuit substrate) is overlaid onthe wiring circuit substrate 46 (first wiring circuit substrate), thewiring circuit substrate 28A (third wiring circuit substrate) isoverlaid on the wiring circuit substrate 33A (second wiring circuitsubstrate), and in addition, the plurality of LSI chips 48 is overlaidoutside of the wiring circuit substrates 28A and 46 (third and firstwiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47H, the individual wiring circuit substrates 46, 33A, and 28Aare preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47H by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47H is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirty-Fourth Embodiment

Hereinbelow, a description will be given of a thirty-fourth embodimentaccording to the present invention with reference to FIGS. 38A to 38C.The thirty-fourth embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 38A to 38C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 38A to 38C, a multilayer wiring circuit substrate 36Jis formed by overlaying the wiring circuit substrates 28A (first andthird wiring circuit substrates) shown in FIG. 1G in the described firstembodiment, and the wiring circuit substrate 50 (second wiring circuitsubstrate) shown in FIG. 9 in the sixth embodiment. The wiring circuitsubstrate 50 (second wiring circuit substrate) is overlaid on the wiringcircuit substrate 28A (first wiring circuit substrate), and the wiringcircuit substrate 28A (third wiring circuit substrate) is overlaid onthe wiring circuit substrate 50 (second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36J, the individual wiring circuit substrates 28A and thewiring circuit substrate 50 are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 36J by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained, and in addition, themultilayer wiring circuit substrate 36J is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Thirty-Fifth Embodiment

Hereinbelow, a description will be given of a thirty-fifth embodimentaccording to the present invention with reference to FIG. 39. Thethirty-fifth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIG. 39 is a cross-sectionalview showing a multilayer wiring circuit substrate of the presentembodiment.

As shown in FIG. 39, a multilayer wiring circuit substrate 36K is formedby overlaying the wiring circuit substrates 28C (first and third wiringcircuit substrates) shown in FIG. 6 in the described fourth embodiment,and the wiring circuit substrate 50 (second wiring circuit substrate)shown in FIG. 9 in the described sixth embodiment. The wiring circuitsubstrate 50 (second wiring circuit substrate) is overlaid on the wiringcircuit substrate 28C (first wiring circuit substrate), and the wiringcircuit substrate 28C (third wiring circuit substrate) is overlaid onthe wiring circuit substrate 50 (second wiring circuit substrate).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 36K, the individual wiring circuit substrates 28C and thewiring circuit substrate 50 are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 36K by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained, and in addition, themultilayer wiring circuit substrate 36K is produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described embodiment are produced, andconcurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher.

Thirty-Sixth Embodiment

Hereinbelow, a description will be given of a thirty-sixth embodimentaccording to the present invention with reference to FIGS. 40A to 40B.The thirty-sixth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 40A to 40C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 40A to 40C, a multilayer wiring circuit substrate 47Iis formed by overlaying the wiring circuit substrates 46 (first andthird wiring circuit substrates) shown in FIG. 7 in the described fifthembodiment, the wiring circuit substrate 50 (second wiring circuitsubstrate) shown in FIG. 9 in the described sixth embodiment, and aplurality of LSI chips 48. The wiring circuit substrate 50 (secondwiring circuit substrate) is overlaid on the wiring circuit substrate 46(first wiring circuit substrate), the wiring circuit substrate 46 (thirdwiring circuit substrate) is overlaid on the wiring circuit substrate 50(second wiring circuit substrate), and in addition, the plurality of LSIchips 48 is overlaid outside of the wiring circuit substrates 46 (firstand third wiring circuit substrates).

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47I, the individual wiring circuit substrates 46 and thewiring circuit substrate 50 are preliminarily manufactured according tomanufacturing methods similar to those in the corresponding embodiments.Subsequently, they are thermally press-bonded to each other by using anoverlaying press so as to be a sandwich-like integral unit. After theoverlaying step, etching is performed for the upper and lower wiringcircuit substrates of the wiring circuit substrate 47I by using resistfilms on the individual upper and lower surface as masks; thereby, aplurality of conductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47I is thereby produced.

In this way according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirty-Seventh Embodiment

Hereinbelow, a description will be given of a thirty-seventh embodimentaccording to the present invention with reference to FIGS. 41A to 41C.The thirty-seventh embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 41A to 41C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 41A to 41C, a multilayer wiring circuit substrate 47Jis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment,the wiring circuit substrate 50 (second wiring circuit substrate) shownin FIG. 9 in the sixth embodiment, the wiring circuit substrate 28C(third wiring circuit substrate) shown in FIG. 6 in the fourthembodiment, and a plurality of LSI chips 48. The wiring circuitsubstrate 50 (second wiring circuit substrate) is overlaid on the wiringcircuit substrate 46 (first wiring circuit substrate), the wiringcircuit substrate 28C (third wiring circuit substrate) is Overlaid onthe wiring circuit substrate 50 (second wiring circuit substrate), andin addition, the plurality of LSI chips 48 is overlaid outside of thewiring circuit substrates 46 and 28C.

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47J, the individual wiring circuit substrates 46, 50, and 28Care preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47J by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47J is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirty-Eighth Embodiment

Hereinbelow, a description will be given of a thirty-eighth embodimentaccording to the present invention with reference to FIGS. 42A to 42C.The thirty-eighth embodiment includes configurations and processingsteps that are substantially common to those in the individualembodiments described above. For the substantially common configurationsand steps, a detailed description will be omitted. FIGS. 42A to 42C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 42A to 42C, a multilayer wiring circuit substrate 47Kis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment, awiring circuit substrate 80 (second wiring circuit substrate) that isspecific to the present embodiment, the wiring circuit substrate 28C(third wiring circuit substrate) shown in FIG. 6 in the fourthembodiment, and a plurality of LSI chips 48. The wiring circuitsubstrate 80 (second wiring circuit substrate) is overlaid on the wiringcircuit substrate 46 (first wiring circuit substrate), the wiringcircuit substrate 28C (third wiring circuit substrate) is overlaid onthe wiring circuit substrate 80 (second wiring circuit substrate), andin addition, the plurality of LSI chips 48 is overlaid outside of thewiring circuit substrates 46 and 28C.

In the wiring circuit substrate 80, which is specific to the presentembodiment, various protrusions extended from one metal layer are formedin the interlayer-insulating layer formed between the upper and lowermetal layers. Specifically, the wiring circuit substrate 80 is composedincluding konide-like protrusions 53 a, the protrusions 53 x, 53 y whichare different in diameter from each other and which are shown in thedescribed thirteenth embodiment, the dummy protrusions 58 formed aroundeach of the protrusions shown in the described ninth embodiment, theprotrusions 53 h each having unique height as shown in the describedeleventh embodiment, and the spacers 61 shown in the described twelfthembodiment. When the wiring circuit substrate 80 is formed, theaforementioned protrusions and the spacers 61 are formed in the samestep.

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47K, the individual wiring circuit substrates 46, 80, and 46are preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47K by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47K is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Thirty-Ninth Embodiment

Hereinbelow, a description will be given of a thirty-ninth embodimentaccording to the present invention with reference to FIGS. 43A to 43C.The thirty-ninth embodiment includes configurations and processing stepsthat are substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIGS. 43A to 43C arecross-sectional views each showing a multilayer wiring circuit substrateof the present embodiment.

As shown in FIGS. 43A to 43C, a multilayer wiring circuit substrate 47Lis formed by overlaying the wiring circuit substrate 46 (first wiringcircuit substrate) shown in FIG. 7 in the described fifth embodiment, awiring circuit substrate 90 (second wiring circuit substrate), ( ) thewiring circuit substrate 28C (third wiring circuit substrate) shown inFIG. 6 in the fourth embodiment, and a plurality of LSI chips 48. Thewiring circuit substrate 90 (second wiring circuit substrate) isoverlaid on the wiring circuit substrate 46 (first wiring circuitsubstrate), the wiring circuit substrate 28C (third wiring circuitsubstrate) is overlaid on the wiring circuit substrate 90 (second wiringcircuit substrate), and in addition, the plurality of LSI chips 48 isoverlaid outside of the wiring circuit substrates 46 and 28C.

As shown in FIG. 43A, the wiring circuit substrate 90 is composedincluding a plurality of conductor circuits 72, a metal layer 74 formedon the conductor circuits 72, through-holes formed so as to pass throughthe insulating substrate, and protrusions 53 formed so as to protrudefrom a base member 51 to the inside of the insulating substrate. Acopper paste 100 is filled in the through-holes and is cured. Highprotrusions 53 h are connected to the copper paste 100, and the lowprotrusions are connected to the metal layer 74. In addition, peripheralportions of the through-holes 73 are covered by the conductor circuits72.

Composing the wiring circuit substrate 90 as described above allows highcircuit integration to be implemented and improves the reliability ofthe connection between the individual protrusions and the individualconductor circuits.

Similarly to the nineteenth embodiment, to configure the wiring circuitsubstrate 47L, the individual wiring circuit substrates 46, 90, and 28Care preliminarily manufactured according to manufacturing methodssimilar to those in the corresponding embodiments. Subsequently, theyare thermally press-bonded to each other by using an overlaying press soas to be a sandwich-like integral unit. After the overlaying step,etching is performed for the upper and lower wiring circuit substratesof the wiring circuit substrate 47L by using resist films on theindividual upper and lower surface as masks; thereby, a plurality ofconductor circuits is obtained.

In addition, the plurality of LSI chips 48 is mounted from the outside,and the multilayer wiring circuit substrate 47L is thereby produced.

In this way, according to the present embodiment, advantageous effectssimilar to those in the described individual embodiments are produced,and concurrently, the multilayer wiring circuit substrate having theplurality of conductor circuits can be obtained. This allows the densityof the wiring circuit substrate to be even higher, and furthermore,allows the LSI chips having a very high integration density to bemounted.

Fortieth Embodiment

Hereinbelow, a description will be given of a fortieth embodimentaccording to the present invention with reference to FIG. 44. Thefortieth embodiment includes configurations and processing steps thatare substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIG. 44 is a perspective viewshowing the overall configuration of the present embodiment.

As shown in the figure, a multilayer wiring circuit substrate 120 isconfigured including spear-like protrusions 57, konide-like protrusions53 a, protrusions 57A similar to those as shown in FIG. 14A in thedescribed tenth embodiment, protrusions 57B similar to those shown inFIG. 14B therein, protrusions 57C similar to those shown in FIG. 14Ctherein, protrusions 57D similar to those shown in FIG. 14D therein,identification marks 63 formed of the same material as that for theaforementioned protrusions either for positioning or identification ofmodels and the like, an identification mark 63 a similar to that shownin FIG. 18B in the described fourteenth embodiment, an identificationmark 63 b similar to that shown in FIG. 18C therein, and spacers 61. Theindividual protrusions are arranged so as to receive a uniformedpressure.

In the described wiring circuit substrate 120, the various protrusions,identification marks, and spacers can be in the same step.

According to the present embodiment described above, advantageouseffects similar to those in the described individual embodiments areproduced, and concurrently, the marks and the individual protrusions canbe formed in the same step. In addition, the spacers are used so as tomake the spacing between upper and lower patterns to be constant,thereby allowing the provision of the wiring circuit substrate thatallows the impedance controllability to be improved.

Forty-First Embodiment

Hereinbelow, a description will be given of a forty-first embodimentaccording to the present invention with reference to FIG. 45. Theforty-first embodiment includes configurations and processing steps thatare substantially common to those in the individual embodimentsdescribed above. For the substantially common configurations and steps,a detailed description will be omitted. FIG. 45 is a block diagram ofthe present embodiment of an electronic apparatus using the individualwiring circuit substrates described above.

Disclosed as the present embodiment is an example electronic apparatus200 in which the described wiring circuit substrates are stacked.

The electronic apparatus 200 is configured including a wiring circuitsection 201 and component members connected to the wiring circuitsection 201. The wiring circuit section 201 has first to N-th wiringcircuit substrates 201-1 to 201-N that are formed by making variouscombinations of the wiring circuit substrates according to the describedembodiments. The component member connected to the wiring circuitsection 201 includes an operation input key 202, a display panel 203, anoscillator 204, a power supply 205, and other devices 206.

Thus, the various types of the wiring circuit substrates according tothe individual embodiments described above can be used in the aboveexample electronic apparatus and various other types of electronicapparatuses requiring high-density circuit integration.

Forty Second Embodiment

Subsequently, a forty second embodiment of the present invention will bedescribed with reference to FIGS. 46A to 46D and 47A to 47C. FIGS. 46Ato 46D an 47A to 47C are cross-sectional views showing production stepsof a wiring circuit substrate of this embodiment.

The outline of the wiring circuit substrate of this embodiment will beexplained. The wiring circuit substrate of this embodiment comprises abase sheet 301, and a laminating sheet 306 to be laminated on one orboth surfaces of the base sheet 301. Here, the base sheet 301 has aninsulating resin 302, wiring films 303 each formed on both surfaces ofthe insulating resin 302, one or a plurality of through holes 304 formedthrough the wiring films 303 and the insulating resin 302, and one or aplurality of conductive materials 305 formed so as to fill the one orthe plurality of the through holes 304. Moreover, the laminating sheet306 has a metal foil 307, and one or a plurality of protrusion parts 308formed, projecting from the metal foil 307 at a position facing to theone or the plurality of the through holes 304. Furthermore, thelaminating sheet 306 is laminated in the state with the one or theplurality of the protrusion parts 308 and the one or the plurality ofthe conductive materials 305 connected.

Here, unlike the conventional example, a copper film needs not be formedby an electroless plating and a subsequent electrolytic plating afterfilling the through holes with the insulating resin in the base sheet301. That is, the through holes 304 needs only to be filled with theconductive material 305 in the base sheet 301 of this embodiment. Theconductive material 305 is preferably made from a copper paste, and asilver paste.

As described later, the laminating sheet 306 may have an etching barrierlayer. The etching barrier layer is preferably made from, for example, anickel (for example by a 2 μm thickness), or a silver (for example by a0.5 μm thickness).

Moreover, it is preferable that the metal foil 307 is made from asilver, or the like and the protrusion parts 308 are made from a copper,a copper alloy, or the like.

Furthermore, a wiring film can be formed by further laminating anotherlaminating sheet (second laminating sheet) on a laminating sheet (firstlaminating sheet) laminated on a base sheet, and patterning a metal foilon the surface of the laminating sheet (second laminating sheet). Or, itis also possible to achieve a multi-layer structure by increasing thenumber of laminations by further laminating a laminating sheet (thirdlaminating sheet) on the laminating sheet (second laminating sheet).

Hereinafter production steps of the wiring circuit substrate of thisembodiment will be explained successively.

Step (A)

First of all, as shown in FIG. 46A, the base sheet 301 as the basemember is prepared. A copper-plated laminated plate with the copper foil303 laminated on both surfaces of the sheet-like insulating resin 302 isprepared. The through holes 304 are formed through the insulating resin302 and the copper foil 303 by drilling or laser processing. Thereafter,a wiring film is formed by selectively etching the copper foil 303 onboth surfaces for patterning.

The production method for the base sheet 301 will be described laterwith reference to FIGS. 48A to 48C. Furthermore, a base sheet producedby the method shown in FIGS. 49A to 49D may be used. The productionmethod will also be explained later in detail.

Step (B)

Subsequently, as shown in FIG. 46B, the through holes 304 are filledwith the conductive material 305. The conductive material is preferablymade from a conductive paste containing a copper or a silver.

Step (C)

Subsequently, as shown in FIG. 46C, two pieces of the laminating sheets306 are prepared so that the laminating sheets 306 are disposed, facingwith both surfaces of the base sheet 301.

The laminating sheets 306 have the protrusion parts 308 on one surfaceof the metal foil made from a copper or a copper alloy (or a metal foilmade from a silver) (corresponding to the “metal layer” in the presentinvention) 307 to be the wiring film (corresponding to the “wiringlayer” of the present invention) at a position corresponding to thethrough holes 304 of the base sheet 301. In the aspect of the presentinvention corresponding to this embodiment, the state before etching isreferred to as the “metal layer”, and the state after the etching isreferred to as the “wiring layer” so as to distinguish the same memberby its state. Moreover, also in other aspects of the present inventioncorresponding to other embodiments related to this embodiment, the sameterminology is partially applied.

Furthermore, the laminating sheets 306 have a bonding sheet 309 formedby bonding at a height lower than that of the protrusion parts 308 onthe surface of the metal foil 307 provided with the protrusion parts308.

Here, the vertex part of each protrusion part 308 projects from thebonding sheet 309. The protrusion parts 308 are preferably made from ametal such as a copper.

The laminating sheets 306 are disposed such that the projectingdirection of the protrusion parts 308 faces with the base sheet 301. Thelaminating sheets 306 are positioned with respect to the base sheet 308such that each protrusion part 308 and each through hole 304 face witheach other.

Step (D)

Subsequently, as shown in FIG. 46D, the laminating sheets 306 arelaminated on both surfaces of the base sheet 301 so as to be integratedby pressuring. At the time, the protrusion parts 308 enter into theconductive material (corresponding to the “conductive member” of thepresent invention) 305 filling the through holes 304 so as to be bondedfirmly. As a result, electric connection between the conductive material305 and the protrusion parts 308 can be provided substantiallycompletely. Furthermore, the metal foil 307 cannot be deflected in thearea with the through holes 304 formed.

Step (E)

Subsequently, as shown in FIG. 47A, a wiring film is formed bypatterning the metal foils 307 on the laminating sheets 306.

The patterning operation is executed by forming a mask pattern byapplication of a resist film, exposure, development, and etching withthe mask pattern used as the mask. Thereafter, the resist film used asthe mask is eliminated. For the selective etching, for example, sprayetching of an aqueous solution of a ferric chloride from both surfacesis preferable.

Step (F)

Subsequently, as shown in FIG. 47B, a solder resist film 310 is formedselectively on the surface of the laminating sheets 306. The numeral 311denotes a recess part formed by the selective formation of the solderresist film 310. The recess parts 311 are formed such that the portionconnected with a solder bump 14 comprising an electrode of an LSI chip313 of the wiring film 307 is exposed. Or, the recess parts 311 areformed such that the part wherein a solder ball 15 is formed is exposed.

By finishing this step, a wring circuit substrate 312 can be completed.

Step (G)

FIG. 47C shows the state with the LSI chip 313 mounted on the wiringcircuit substrate 312. The numeral 314 denotes a solder bump, 315 asolder ball for connecting the wiring circuit substrate 312 of thisembodiment with an unillustrated mother board.

Although an example of the wiring circuit substrate 312 as a multi-layerwiring substrate for the semiconductor package is described here, it canalso be used as a mother board.

As mentioned above, according to this embodiment, the wiring circuitsubstrate 312 is formed by filling the through holes 304 with theconductive material 305. Accordingly, formation of a copper film for thewiring film formation by an electroless plating and a subsequentelectrolytic plating can be eliminated after filling the through holesof the copper-plated laminating plate. Therefore, a problem ofdifficulty of providing a sufficient copper film thickness can beprevented as well as the risk of generating film thickness irregularitycan be avoided.

Besides, the copper film for the wiring film formation cannot bedeflected in the area with the through holes 304 formed. Accordingly,the wiring film 307 can be formed relatively easily with a sufficientthickness and a minute pattern.

Moreover, the protrusion parts 308 of the laminating sheets 306 areconnected, entering into the conductive material 305 filling the throughholes 304. Therefore, electric connection between the laminating sheets306 and the base sheet 301 can be better and certain, and thus a wiringcircuit substrate can be formed with a simple production process and ahigh reliability.

Forty Third Embodiment

A forty third embodiment of the present invention will be described withreference to FIGS. 48A to 48C. FIGS. 48A to 48C are cross-sectionalviews showing an embodiment of production steps of a base member (basesheet) to be used in the above-mentioned wiring circuit substrate.

Hereinafter, the production steps of the base sheet of this embodimentwill be explained successively.

Step (A)

As shown in FIG. 48A, a three-layered laminating member with bothsurfaces copper-plated is prepared as the base member for the base sheet301.

The laminating member is formed by laminating the copper foils 303 onboth surfaces of the sheet-like insulating resin (corresponding to the“insulating layer” of the present invention) 302.

Step (B)

Subsequently, as shown in FIG. 48B, a wiring film comprising a circuit(corresponding to the “metal wiring layer” of the present invention) 303is provided by patterning the copper foils 303 on both surfaces of thebase sheet 301 by selective etching.

The selective etching for patterning is executed by applying a resistfilm, exposure, development for patterning, and etching the silver foils303 with the patterned resist film used as the mask. After finishing theetching, the resist film is eliminated.

Step (C)

Subsequently, as shown in FIG. 48C, the through holes 304 are formed by,for example drilling. Or the through holes 304 are formed by laserprocessing. It is preferable to form the through holes 304 with a holesize of about 0.1 to 0.3 mm.

As mentioned above, production of the base sheet 301 is executed.

Forty Fourth Embodiment

A forty fourth embodiment of the present invention will be describedwith reference to FIGS. 49A to 49D. FIGS. 49A to 49C are cross-sectionalviews showing an embodiment of production steps of a base member (basesheet) to be used in the above-mentioned wiring circuit substrate.

Hereinafter, the production steps of the base sheet of this embodimentwill be explained successively.

Step (A)

As shown in FIG. 49A, similar to the above-mentioned forty thirdembodiment, a three-layered laminating member with both surfacescopper-plated is prepared as the base member for the base sheet 301.

The laminating member is formed by laminating the copper foils 303 onboth surfaces of the sheet-like insulating resin 302.

Step (B)

Subsequently, as shown in FIG. 49B, the through holes 304 are formed by,for example drilling. Or the through holes 304 are formed by laserprocessing. The hole size (diameter) of the through holes 304 ispreferably about 0.1 to 0.3 mm.

Step (C)

Subsequently, an electroless copper plating process is executed on theentire surface. Thereafter, an electrolytic copper plating process isexecuted on the entire surface. Accordingly, a copper film 303 a isformed as shown in FIG. 49C.

Step (D)

Subsequently, by selectively etching the copper film 303 a, a wiringfilm as shown in FIG. 49D is provided. The etching is executed byphotolithography using a resist film. Accordingly, the base sheet 301 isformed.

As the base sheet 301 used in the wiring circuit substrate of thepresent invention, any one produced in either of the production methodsdescribed in the above-mentioned embodiments can be used.

Forty Fifth Embodiment

A forty fifth embodiment of the present invention will be described withreference to FIGS. 50A to 50D. FIGS. 50A to 50C are cross-sectionalviews showing an embodiment of production steps of a laminating sheet tobe used in the above-mentioned wiring circuit substrate.

Hereinafter, the production steps of the laminating sheet of thisembodiment will be explained successively.

Step (A)

As shown in FIG. 50A, a laminating plate obtained by laminating a metallayer (of, for example a 100 μm thickness) 308 made from a copper or acopper alloy on the surface of a metal base member 307 made from, forexample a silver (of, for example, a 12 μm thickness) is prepared.

Step (B)

Subsequently, as shown in FIG. 50B, a resist film 318 is formedselectively on the surface of the metal layer 308 made from a copper ora copper alloy. The resist film 318 is to be used as an etching mask inthe etching for forming the protrusion parts 308. Accordingly,application, exposure and development of the resist film 318 areexecuted.

Step (C)

The protrusion parts 308 are formed by selective etching of the metallayer 318 with the resist film 318 used as the mask. Thereafter, theresist film 318 is eliminated. FIG. 50C shows the state aftereliminating the resist film 318. For the etching, for example, analkaline etching liquid is used preferably.

Step (D)

Subsequently, as shown in FIG. 50D, a bonding sheet 309 with a heightlower than that of the protrusion parts 308 is attached on the surfaceof the metal base member 307 with the protrusion parts 308 formed.Therefore, the vertex part of each protrusion part 308 projects from thesurface of the bonding sheet 30.

In the case the laminating sheet 306 is used, the metal base member 307made from a silver, corresponding to the surface of the laminating sheet306 is etched selectively so as to form the wiring film 307. Therefore,the wiring film 307 on the surface of the wiring circuit substrate ismade from a silver.

Forty Sixth Embodiment

A forty sixth embodiment of the present invention will be described withreference to FIGS. 51A to 51D. FIGS. 51A to 51C are cross-sectionalviews showing an embodiment of production steps of a laminating sheet tobe used in the above-mentioned wiring circuit substrate.

Hereinafter, the production steps of the laminating sheet of thisembodiment will be explained successively. The laminating sheet 306 a ofthis embodiment has a larger number of layers compared with that of thelaminating sheet 306 shown in FIGS. 50A to 50D.

Step (A)

As shown in FIG. 51A, an etching barrier layer 319 is formed on thesurface of the metal base member 307. Here, it is preferable that themetal base member 307 is made, for example, from a copper with a 18 μmthickness. Moreover, it is preferable that the etching barrier layer 319is made, for example, from a nickel with a 2 μm thickness. Furthermore,it is preferable that the etching barrier layer 319 is made, forexample, from a silver with a 0.5 μm thickness.

The metal layer 308 is further laminated on the surface of the etchingbarrier layer 319. It is preferable that the metal layer 308 is made,for example, from a copper, or a copper alloy, with a 100 μm thickness.

Accordingly, a laminating plate formed with the three-layer structureincluding the metal base member 307, the etching barrier layer 319, andthe metal layer 308 is prepared.

Step (B)

Subsequently, as shown in FIG. 51B, the resist film 318 is formedselectively on the surface of the on the surface of the metal layer 308made from a copper or a copper alloy. The resist film 318 is to be usedas an etching mask in the etching for forming the protrusion parts 308.Accordingly, application, exposure and development of the resist film318 are executed.

Step (C)

Subsequently, the protrusion parts 308 are formed by selective etchingof the metal layer 318 with the resist film 318 used as the mask.Thereafter, the resist film 318 is eliminated. For the etching, forexample, an alkaline etching liquid is used preferably.

In the etching, the etching barrier layer 319 provides a function forpreventing damage on the metal base member 307 made from a copper by theetching. FIG. 51C shows the state after eliminating the resist film 318.

Step (D)

Subsequently, as shown in FIG. 51D, a bonding sheet 309 with a heightlower than that of the protrusion parts 308 is attached on the surfaceof the metal base member 307 with the protrusion parts 308 formed.

Therefore, the vertex part of each protrusion part 308 projects from thesurface of the bonding sheet 30.

Accordingly, the laminating sheet of this embodiment is formed.

Forty Seventh Embodiment

A forty seventh embodiment of the present invention will be describedwith reference to FIGS. 52A to 52F and 53A to 53C. FIGS. 52A to 52F arecross-sectional views showing an embodiment of production steps of alaminating sheet to be used in a wiring circuit substrate of thisembodiment. FIGS. 53A to 53C are cross-sectional views showing anembodiment of production steps of a wiring circuit substrate of thisembodiment.

Hereinafter, the production steps of the wiring circuit substrate ofthis embodiment will be explained successively.

Step (A)

First of all, as shown in FIG. 52A, a metal plate 321 made from a copperof, for example, about 100 μm thickness is prepared.

Step (B)

Subsequently, as shown in FIG. 52B, a photosensitive insulating resinlayer 322 is applied. The photosensitive insulating resin layer 22 ispatterned by exposure and development. The numeral 323 denotes a holeformed by the patterning. The hole 323 is formed, corresponding to thearea with the protrusion parts 28 described later formed.

Step (C)

Subsequently, an electroless copper plating process is applied on theentire surface of the photosensitive resin layer 322. The process isexecuted preferably with, for example, a 0.5 μm copper platingthickness.

Thereafter, a resist pattern by plating is formed selectively. A wiringfilm 324 comprising a copper film is formed by electrolytic copperplating with the resist pattern used as the mask. The wiring film 324 isformed preferably with, for example, a 20 μm thickness.

Then, the resist pattern is eliminated. Furthermore, the copper film(0.5 μm thickness) by the electroless copper plating is etched with thewiring film 324 used as the mask. Accordingly, the wiring films 324 areseparated independent with each other. FIG. 52C shows the state afterthe etching. For the etching, for example, a release agent is usedpreferably.

Step (D)

Subsequently, as shown in FIG. 52D, an insulating layer 325 is formed soas to cover the wiring film 324 selectively for forming an opening 326in a part to be provided with a connection terminal.

Step (E)

Subsequently, by an electrolytic plating, a protrusion-like micro ball327 with a multi-layer structure made of nickel/gold is formed. Theelectrolytic plating is executed preferably to form a nickel by, forexample, 50 μm, and then a gold by, for example, 0.3 μm. substantiallycompletely. Accordingly, a wiring circuit substrate 331 of thisembodiment is formed.

Step (C)

Moreover, as shown in FIG. 53C, an LSI chip 313 is mounted on the wiringcircuit substrate 331, and a solder ball 315 is placed thereon. Thenumeral 314 denotes a solder bump, and 315 a solder ball for connectingthe wiring circuit substrate 331 of this embodiment with anunillustrated mother board.

Although an example of the wiring circuit substrate 331 as a multi-layerwiring substrate for the semiconductor package is described, it can alsobe used as a mother board.

Although a multi-layer structure with the laminating sheets 330 or thelaminating sheets 306 laminated on both surfaces of the base sheet 301has been described in the above-mentioned embodiments, a multi-layerstructure with the laminating sheet 330 or the laminating sheet 306laminated on one surface of the base sheet 301 can be adopted as well.

Furthermore, a wiring circuit substrate with one or a plurality of thelaminating sheets 306, 330 (second laminating sheet) further laminatedon both surfaces or one surface of the wiring circuit substrate 312, 331can be provided in the above-mentioned embodiments. Accordingly, afurther multi-layer structure of the wiring circuit substrate can beachieved.

As mentioned above, the laminating sheet is laminated on one surface orboth surfaces of the base sheet. At the time, the protrusion parts ofthe laminating sheet and the conductive material for filling the throughholes of the base sheet are connected. Therefore, the wiring film of thelaminating sheet cannot be deflected in the area with the through holesformed. Besides, the wiring film of the base sheet needs not be formedby an electroless plating and a subsequent electrolytic plating.Accordingly, the film thickness can be evened at a necessary thickness,and thus minute wiring can be enabled.

Moreover, the protrusion parts of the laminating sheet are connected soas to cut into the conductive material filling the through holes.Therefore, the adhesion property can be strengthened so that electricconnection between the laminating sheet and the base sheet can be betterand certain, and thus a wiring circuit substrate can be formed with ahigh reliability of the inter-layer connection by a simple production.

Furthermore, since a laminating sheet can be laminated further on theoutside of another laminating sheet, a multi-layer structure of a wiringcircuit substrate can be provided by a relatively simple process so thatsimplification of the production steps and reduction of the entireproduction time can be achieved as well.

As above, while the invention has been illustrated and described indetail with reference to the specific embodiments, it will be understoodthat those skilled in the art effect various modifications withoutdeparting from the spirit and scope of the invention. Furthermore, it isa matter of course that the invention includes combinations of thedescribed embodiments, and in addition, combinations of the describedembodiments and their modifications.

Furthermore, the etching-barrier layer is preferably made from, forexample, a titanium (Ti), a tin (Sn), a solder, an aluminium (Al).

1. A method of manufacturing a multi-layer wiring circuit substrate,comprising: providing a first metal layer having a first major surfacewith a patterned mask layer overlying and exposing first areas of saidfirst major surface and covering second areas of said first majorsurface; selectively etching said first metal layer in said first areasof said first major surface to reduce a thickness of said first metallayer in said etched first areas and to form protrusions in said secondareas, said protrusions extending above said etched first areas; formingan interlayer-insulating layer overlying said etched first areas of saidfirst major surface, said interlayer-insulating layer having an innersurface confronting said etched first areas and an outer surface remotefrom said inner surface such that said protrusions extend through saidinterlayer-insulating layer and have ends exposed at said outer surface;providing a second metal layer in conductive communication with saidexposed ends of said protrusions; selectively patterning said firstmetal layer from a second major surface of said first metal layer remotefrom said first major surface; and selectively patterning said secondmetal layer from an exposed major surface of said second metal layerremote from said interlayer-insulating layer.
 2. The method as claimedin claim 1, wherein said steps of selectively patterning said first andsecond metal layers are performed simultaneously.
 3. The method asclaimed in claim 1, wherein said step of selectively patterning saidfirst metal layer is performed at a different time from said step ofpatterning said second metal layer.
 4. The method as claimed in claim 1,further comprising coating said ends of said protrusions with a materialincluding a conductor prior to forming said interlayer-insulating layer.5. The method as claimed in claim 4, wherein said step of coating saidends includes applying a metal to said ends.
 6. The method as claimed inclaim 5, wherein at least one of gold or solder is applied to said ends.7. The method as claimed in claim 4, wherein said step of coating saidends includes applying one of a conductive paste or an anisotropicconductive film to said ends.
 8. The method as claimed in claim 1,further comprising roughening said exposed ends of said protrusionsprior to said step of providing said second metal layer.
 9. The methodas claimed in claim 8, wherein said step of roughening includes sprayetching said ends of said protrusions after said step of selectivelyetching said first metal layer to form said protrusions.
 10. The methodas claimed in claim 1, wherein said patterned mask layer includesindividual mask patterns having diameters smaller than diameters ofindividual ones of said protrusions, such that said step of selectivelyetching produces protrusions having spear-like shape.
 11. The method asclaimed in claim 1, further comprising removing said patterned masklayer and subsequently etching said protrusions to cause saidprotrusions to become spear-like in shape.
 12. The method as claimed inclaim 1, wherein said step of selectively etching said protrusionsincludes forming protrusions having drum-like shape.
 13. The method asclaimed in claim 1, further comprising removing unnecessary ones of saidprotrusions prior to completing said steps of selectively patterningsaid first and second metal layers, wherein said step of removing saidunnecessary protrusions includes over-etching said unnecessaryprotrusions while preserving others of said protrusions.
 14. The methodas claimed in claim 1, wherein said first and second metal layersinclude copper.